Dec 22, 2015

Contagion: Christmas update.

Probably the last update for this year. Oh well.


-Updated all maps with Christmas props\materials. Those do not have any collision to avoid possible issues with navigation;

-Sig Sauer accuracy improved;

-Tweaks to Mossberg and Remington shotguns. Mossberg is now great against hordes, yet Remington is great against single targets(Riot police zombies for example);

-Some balance tweaks for Flatline waves on all maps(because people are really having hard time and always dies horribly);

-Zombies got Christmas stuff on em(Santa's hats for example);

-Fixed some glitches on Campwhitner;

-Added visual dropdown menu for users who dont like Christmas update. You can find it in Multiplayer options;

-Phone viewmodel has been updated;

-Sig Sauer viewmodel has been updated.

I guess this is going to be our last update in 2015 year. Oh well.

We are still working on release by the way, so dont expect the update goes up that quickly.

Thanks for reading and good luck in future.

Dec 16, 2015

Contagion: Hotfix for Flatline\Escape gamemodes.

An hotfix patch has been released for Contagion.


-Attempts to fix problem with camera angle when roaches attaches to Survivor;

-Hint system for Flatline gamemode(WIP);

-Fixed bunch of bugs in CF_Campwhitner\CF_Montclair;

-Hopefully, fixed problem with culling system in Escape gamemode, causing no zombies to show up during whole map(except of escape sequences);

-Fixed bug with cleanup system removing pistol\medkit\pocket lights when first wave havent started yet;

-Removed not needed stuff from Hunted gamemode;

-Fixed invisible phone display glitch whenever respawning as Survivor between waves;

-Removed collision for cockroaches to prevent weirdness.

-Hopefully fixed issue with spectator's camera when cockroach attaches to Survivor.

Additional information:

If you found glitch or just want to discuss Flatline, feel free to post in new sub-forums a.k.a.

-Thanks and have fun.

Dec 12, 2015

Contagion: Flatline beta update is out!

As we promised. Flatline gamemode...

...but you should keep in mind this is a beta stage only.


A: Because we want see people's feedback on Flatline gamemode. We want to see what people like in Flatline and what people dont. Its simple really. People always can submit their feedback on our forums and share their thoughts there. (As long as people not breaking any forum rules and such.)
People can also help us to find some glitches(if we ever missed any which I believe we did missed some) and submit them in our forums again. Simple really. 
On top of that, we have encountered some issues that cant be resolved right away and it will take a good time for us to resolve it, which isnt great when we wish to release patch this year.
Yet I am afraid people will not understand that right.

Besides of Flatline, we got other cool stuff to share with you!

Full changelog:

-Added Flatline gamemode(BETA);

-Added 2 new maps: CF_Montclair and CF_Campwhitner;

-Added "Flatline BETA" gamemode icon whenever setting up\looking for server;

-Improved Remington 870. Sights looks much more cooler and realistic;

-COCKROACH VISION. Almost like in Sin City movie(Wish to tweak that color correction a little so it will show off colored blood and fire). To activate cockroach vision, press "flashlight" button(F button by default). Make sure post processing is set at least to medium, otherwise you wont see it;

-Cockroaches can now attach to players. To do that, stay near by player and press "use" button(E by default)(REALLY WIP);

-Bug fixes for CE_Montclair map.

-Changed 9MM bullet behavior. Multikills are still possible but those are rare. You cant penetrate through Riot Police zombie armor now. Shooting at door is now pointless, as the bullet wont go through(except if door is almost broken or got missing window on it).

-A lot changes in code just for Flatline gamemode.

Other information...

As we know, the workshop manager is fixed which is great, however it requires more fixes on this case. Our team already know about that and will resolve this as soon as assistant programmer will have time for it.

If your Steam client havent updated Contagion yet, you can either restart Steam client or do full game cache check.

-Thanks and have fun!

Nov 5, 2015

Contagion: Things we are working on and other information.

Well, I have to update my blog anyway...

Recent events happened:

Fixed AI attacking height glitch.
We have released a new map called: Montclair. Escape\Hunted gamemode.
Fixed bunch of problems including shortcuts in Barlowe Square.
New props released.
Halloween event.
A Humble Bundle 4pack with great discount.

Currently working on\done already list:

We finally found out whats going on with Montclair map crashing servers\clients.
Removed all Halloween assets.
(Personally by me)Tweaked Harvest navigation file, so players will have less chance to sit around and camp like an idiots while AI zombies will be stuck and have no idea how to navigate to guy.
Recompiled all maps with updated stuff.
CH_Harvest map.
Probably more, as I cant remember everything...

I personally hope the hotfix patch will be released today or maybe tomorrow. Only main developers know when release stuff.

Other information:

Slowly learning navigation files and how do they work so I can give a helping hand to our level designers and fix those bloody navigation issues.
I am also playtesting Sven Co-op 5.0 version that will be available on Steam soon.

To do list:

Tutorial for porting Source content into GoldSrc. Most likely it will be simple props and weapon models.
I couldnt really find anything useful in Internet to be honest, so I had to figure everything out by myself. Fun stuff.
Trying to port Source player model into GoldSrc properly, so it wont have any issues much.
Also trying to port Source player models into Contagion game. Problem is only a bone setup that is bugging hell-out player model. Oh well.

I am sorry for keeping this really short and updating blog that late but, we are all busy in this worthless world.
Thanks for reading and good luck!

Sep 12, 2015

Contagion: DLC characters are out.

And here it is. DLC characters.

Today's update brings some fixes, allowing players officialy play as new DLC characters such as:
Mia, Manuel, Curtis, Yumi.

Chamgelog from my broken mind:

-DLC characters added.

-Voice lines for all DLC characters compiled and now they are added.

-Fixed scoreboard issue with DLC characters portraits being missing.

-Fixed(hopefully)metal ladders. Should be possible to use them in Pioneer Express, Aurora Estates, Barlowe Square.

-Gasmask issues has been fixed. (W_ models and incorrect gasmask placement position on DLC characters.)

Thanks and have fun.

Aug 6, 2015

Contagion: DLC weapons are out again!

New DLC weapons are out and everyone can take them away now!

Our team have finally fixed the biggest problems that came up once we released DLC weapons for the first time: VAC connection failure. Now when that bloody thing is fixed, we can release new weapons easily hoping for no other major glitches to come up with.

New DLC weapons:
M1 Garand
Remington 870

Thanks and have fun!

Jul 22, 2015

Contagion: DLC weapons and reason why they arent in game yet.

Somewhere in July, we have released DLC weapons. Everyone was happy until we found some serious issues with those .dlls. In this message, I'll try to explain the situation and reasons for rolling back update.

Wait, the hell you talkin about? DLC weapons? Are you sold out or something?

No. It appears to be, some players still havent heard anything about our free DLC bundle that contains:
-4 new characters: Mia, Curtis, Manuel, Yumi.
-4 new weapons: SCAR, M1 Garand, Compound Bow, Remington 870.
-3 new maps(originally planned 2): Harvest, UnionStation, CampWhitner.
-And some fixes for Contagion game itself.

Oh the situation?

In July, we released those new weapons and it was ready for public use. However, after few hours, me and other playtester have found some serious issues going on after releasing those new weapons such as:
-Texture glitches on cretain props.
-Connection to VAC servers failure.(Reported by fellow mates of mine)
-Sound glitches on new weapons.
-Code related issues.
And on top of that: The upload on Steam network was faster than expected and because of that, the patch itself got corrupted.
After spotting these issues, our team rolled back update and all those weapons are locked for public use at this moment.

How long until we can get those weapons again?

Dont you even ask me that kind of question.
It all depends on our programmer at this moment, as well on VALVe. We have requested assistance and still waiting for their response.

You'll get the stuff once we'll fix the stuff.

You can always keep an eye on our progress and for status updates in this thread.

(Also this is just an quick heads up message.)

-Thanks and have fun.

Jun 25, 2015

Steam Review System. The good and the bad.

Steam Review System. Is it good or not? It depends on situation.

The Good:

You can share your opinion about game\software\video with other Steam users. Either its would be an public view or friends only.
You can describe whats good and whats bad about game\software\video.
Multi-language supported.
BBcodes are supported.
Developers can personally respond on your review.
Other users can comment on your review.

The Bad:

Users can be extremely rude in their reviews.
Information cant be verified, unless you did research on game\software\video.
Lying reviews can get on top of game\software\video store page.
Reviews can also contain information about developer rather than game\software\video.
Reviews can also contain some information that is completely not related to game\software\video. Example would be: Food recipes or how someone had a good time with their hand.
Reviews rarely gets moderated by VALVe employers, unless developers and\or moderators requests to do so.
Other users can also like\dislike your review. In some cases, some users may find your review funny.(Which is completely useless option to be honest.)

Now, allow me to voice my personal opinion on bad points.

Users can be extremely rude in their reviews.

Some users perfer to swear instead of looking for some ways how to explain the stuff without swearing.
Some users even abuses with that and instead of creating proper review, all I can see is a simple swearing and butthurt.
Rage about something that user didn't like in game\software\video.

Information cant be verified, unless you did research on game\software\video.

Some reviewers hopes for people to blindly believe them without doing any research.
Even if they do provide their evidence, you gotta remember that any evidence can be modificated\edited. It is advised to do some research by yourself and ensure the guy writes the truth.
Few guys got banned for rule breaking forums, yet the reviewer claims that they got banned for nothing.

Lying reviews can get on top of game\software\video store page.

Sadly enough, most people blindly believes in lying review and keeps liking the review and hoping for review to get on top of game\software\video store page.
Example: Contagion video game. Right now, it does has some lying reviews there that contains misleading information and most people blindly believed in this information.

Reviews can also contain information about developer rather than game\software\video.

Review System was built for reviewing the stuff such as game\software or a video not for discussing developer. If you got personal problems with developer, either add him on Steam Friends and discuss everything or post your feelings about developer somewhere else. 
For example: At Facebook, Twitter, Reddit or even in worse places. 
Posting review about developer considers as abuse and can be flagged by developer\moderators resulting for your review either to be deleted\locked down.

Reviews can also contain some information that is completely not related to game\software\video. Example would be: Food recipes or how someone had a good time with their hand.

Once again: Review System was built for review the video game. 
Nobody gives a damn thing about food recipe, because we can view it on Internet by ourselves.
Example: TF2 video game.
Nobody gives a damn thing about someone having a good time with their hand. You dont even need to ask why.
Example: Some visual novel games such as: Sakura Spirit\Sakura Angels or else.

Reviews rarely gets moderated by VALVe employers, unless develoepers and\or moderators requests to do so.

Which I think it is true. I havent seen other reviews gets moderated unless developers and\or moderators requested to check out the review for suspicious activity.
For example: Contagion video game. I personally request developers for check out before requesting VALVe employers to check out review and do next steps in moderation.

Other users can also like\dislike your review. In some cases, some users may find your review funny.(Which is completely useless option to be honest.)

Like\dislike buttons are quite fine, but they can be abused a lot. 
Examples: Fake Steam accounts, blindly believing people, random clicks, else.

While other people was requesting an option to sort reviews that is pointless or else, VALVe decided to add "Funny" option on reviews.
In my opinion: This is completely useless option. Sure, there might be some fun reviews, but I am actually looking for constructive reviews instead of some pointless joke reviews.


The review system is good and bad at same time. This is my personal view on review system.
It is sad for me, when I see bunch of people breaking rules or uses review system to express their hate on something\someone. But I do like review system when users follows the rules and gives constructive feedback on stuff.
However, once review system were added, I already had a bad feeling about that. Because you know...Steam.

Once again, this is my personal view and opinion on this system. You may\may not agree with this one, but do not provoke\start any other flame wars about that.

Thanks and have fun.

Jun 13, 2015

Contagion: First wave of free DLC bundle.

Just what exactly people asked for: New maps!


From the recent update:
Added new maps: CE_Harvest, CE_Campwhitner, CX_Campwhitner, CH_Harvest, CH_Campwhitner, CH_UnionStation.

Optimized, Fixed exploits, Bugs, and improved game-play for both Barlowe Square and Pioneer Express.

Added numerous assets for multiple maps.

Replaced old assets with newer & better versions.

That's all for now. Remember: This is a first update regarding to our free DLC bundle.
Our team is sorting out issues with Flatline,weapons and charachters and they'll be in-game shortly.

Thanks and have fun.

Apr 17, 2015

Steam: Phishing bots, whining people, private profiles. (Updated)

Ah, we all remember that recent invasion of phising bots adding you sometimes and sending you suspicious links.

Phishing bots.

We all know their action. They adds you, they automatically sends you a message with phishing link, someone presses that link, downloads .scr file and loses all their "expensive" inventory.

It is simple one yet nobody was paying attention for that one earlier, until people started really crying on Steam forums and begging Steam to do something.
Guess what? 
Steam actually did some improvements on security, yet people still falls into that scam.
Their improvement was simple. Trade offers confirms by using email message with specific code in it. That .scr file was used to create simple trade offers, offering to phishing bot all other guy inventory in exchange for nothing. Now when that thing was added, these .scr files are not working much nowadays. Sadly enough, people started complaining even about that thing as well. Its like, VALVe trying to help people, yet they are recieving whines and crying everywhere.

Whining people.

Now this is an interesting part that I love most of times.
Everytime when I am checking out Steam forums(because I am bored), I can see at least 2 people complaining about phishing bots adding them. So I am checking their profile and guess what?
User who complains got:
  • Open profile and everyone can view it.
  • Open inventory and everyone can view it.
  • Everyone can comment on his profile.
  • Being member of trade or large amount of other members groups.
Suspecting the guy is another useless trader on Steam, I believe the guy is also being active on different trade forums or on some crappy "betting" websites.

Now I am asking question myself: Before complaining about one thing, have you worked on your side first? I suppose not.

There is a fun fact: None of these bots EVER added me on Steam. None at all.
Why? Because some little things can help you in some problems.

So here is what I want you to recommend:

  • Set your profile to "Private\Friends only". That way, you are locking random peoples access to your profile and they cant view anything. Only you or your friends(if you set your profile to "friends only") can view your stuff.
  • Set your inventory to private. Even Steam gifts should be hidden away.
  • Remove ability to comment on your profile. Set it to private and by doing this: Nobody will ever write you any kind of crap on your profile. Your friends can always contact with you by using private messages. Doesnt matter if you are online or offline. They can. In this case, what the point of having comments? There is none.
  • Leave Steam groups. Keep your group limit up to 10. Stay away from trade groups\large member groups.
  • Dont be part of member on trade forums or even worse, on some shitty "betting" websites.
  • Try not to add random people on your friends list, unless you know them or played with them in one game session.
  • If your friend have sent a link to you(doesnt really matter which one but, most of times you'll get link with some kind of image, video or something else.) Of course, you may get suspicious about these links but, there is one simple way to check out if the link is using true colors or not. How? Simple.Clicking on this link, you'll get access to the website that reveals other URLs. It shows URLs real destination and you by doing that, you can always view and decide what next action should be taken.
  • And last thing: Keep your antivirus software updated all time. They helps you a lot.
It is so damn simple, yet people really...crying about that. Simple things like above can solve a lot problems. And dont tell me it will cause the problem. It wont cause any problems.
It'll be better for you to do these steps before its too late. Some users have reported about specific datebase holding some users information about their inventory and these bots are simply spamming them with their requests just to try their luck.
Of course, not much people understand these steps and believes it wont help them. I bet those kind of people didnt even tried to complete these steps.

Private profiles.

Ah, I love when people complaining about private profiles and treats them as some kind of biological weapon that will kill them if they ever touch the weapon.
It reminds me terrible Payday 2 community that will always kick you from random lobbies just because you got profile set to private.(Dont want to derail much about it.) But guess what? That kind of...problem spreaded to whole Steam community now. Most of times, if you gonna add some guy, he will probably block you because of your profile settings. Its quite fun to watch at these retarded people but, thats their profile and they can take whatever actions they like.

There is one fact that cant be argued much: 
If the person got private profile, its up to him. You cant enforce the person set his profile to public. 
If he want to hide something, its up to him. Who knows, maybe the guy is being stalked by some suspicious people?

I dont really care if the person who is reading this message at this moment is just average user of Steam, useless trader on Steam or just new guy who arrived to Steam platform recently.

Its completely your choice what privacy settings you need. Nobody elses like I wrote above.
If you got blocked, dont get surprised. Confused and retarded people will always act like that, until Steam(in complaining mates view) will do something about it(while Steam already did their best).

*Update 4.20.2015*

Just discovered an new rule created by Steam:
All new created accounts can no longer send friend requests\open group chat\vote in Workshop\Greenlight pages and more. To remove this restriction, newly created accounts must pay 5$(Either keep them in Steam wallet or buy some games).

In my opinion, this is a good thing, although I can already see people complaining. I mean, sure, some people arent able to pay 5$ due the finance reasons\dont have credit car\wallets such as paypal\webmoney\else. I understand these guys but, you people complaind so damn much about "bots" adding you in friends list. You complained>Valve did some updates>now instead of saying "Thank you for trying to solve the problem.", you people are just complaining even more.


Its quite pathetic to see people whining and complaining about private profiles, as well as users adding you on Steam. Those kind of people believes that Steam did nothing for them. If you havent noticed yet, Steam actually did a lot improvements for your security. Of course people complains about these improvements as well but, trust me. These improvements helps you a lot.
Mind you that Steam is private company and they decide what kind of actions to take, not anyone elses.
If you got your head with proper brain installed in it, you'll be safe. 

I really hope those steps above will somewhat help you, thank you for reading the message and good luck in future.

Apr 10, 2015

Support Monochrome team at Indies Crash E3!

Support our team at Indies Crash E3 party.

You dont need to be a member of website, you dont need to pay or something. You just need an valid email. Just click on this link and press "Support" button. The party ends at April, 26, so please, be sure to vote.

DLC news.

While I see people are getting kinda tired of waiting for DLC, I can give some information about our status of DLC.
  • The characters are all ready. (We just need work on UI parts, so people will be able to select one character out of 12. An free upcoming DLC will bring 4 new characters.)
  • The weapons are ready for shooting. (I personally believe some animations needs more tweaks, but who cares?)
  • Maps are ready to be played. (There still some minor glitches though.)
  • Gamemode Flatline is being worked on. I know, people cant wait for that moment, but to avoid dissapointing people, we need adjust the stuff there.
  • Possibly but cant promise: An new Escape\Extraction\Hunted map that wasnt mentoined at all might be added in our DLC.
The release is planned in April and not anymore later. Please, stay tuned for news in our Official group, keep an eye on forums and announcements there.

-Thanks and have fun.

Mar 14, 2015

Contagion: The game is alive.

I guess its a right time to explain that kind of stuff.

Why I wrote this message?

Starting from January, some people got extremely confused about our status of Contagion game. I've seen a lot negative reviews or posts on forums or just simple rage in chat of other games.
Most negative reviews or posts was like:
Devs abandoned the game. They dont care and all they want is money.
Or like:
Developers hopes for moddes to create new maps\custom content in Workshop, while they(developers) are chilling. 
Or even like:

Now. Allow me to explain this stuff.

Our team never abandoned the game. We are working on game. I can see the progress being done by developers every day, especially when I am updating developer build. I understand, you people really want some new stuff or bug fixes, but for God's sake, give us some time to create all that stuff.
Phahahahahahahaha. People these days. If you havent read our announcement as well as pinned thread about delays, story, I suggest you to leave this page and find that pinned thread and announcement and read it. Carefully.
Nobody from our team looked for excuses. Things happens. Deal with it.

Our team is also working on new content. The upcoming DLC will include:
2 news maps;
4 new characters;
4 new weapons;
1 new gamemode.

Now. Stop lying about "Nobody plays the game"

Every time when I am checking server browser, I can see players playing on NY\Cali\UK servers most of times. Also, ever heard about time zones? Not everyone lives in your country and not everyone got same time zone as yours. Keep that in mind.

In short: The game is alive and we are working on it. Just because game had no updates in few months, doesnt mean we stopped working on Contagion. Do an research. Read our announcement, read our pinned thread in Contagion's forums. Read it carefully and understand us properly.

-Thanks and have fun.

Feb 2, 2015

1 year at Monochrome.

An simple "Yay" message.

Its been one year since I joined Monochrome team.

And Hell. I still remember those words from Dec;
Hay. Can't remember if I messaged you yet but I was curious if you'd be interested in joining the Contagion official playtesting team?
At that moment, I thought I am blind a little(drunk after celebrating New Year, yeah), but after re-viewing everything I realized the question was live on Skype and I am not blind yet(Thankfully).

I wasnt sure about time-zones and how they were working earlier, but after explanations from Dec, I was like:
Sure, I am glad to help you and your team as well. 
I was feeling much better than last 3 years after getting that message from Dec and when Brian (Tatsur0) was accepting the document as well as explaining completely everything to me.
I finally had a feeling I am somewhat useful here for now. (I still got that feeling in my injured body.)

I am glad to be part of Monochrome team. I do enjoy playtesting everything what I can in Contagion, helping people on forums, keeping in check the whole Contagion hub as well as speaking with developers about some cool stuff and knowing what future we got in our minds.

I personally would like to thank;
Dec for being a cool guy, inviting me in team, sorting\sending documents to me.
Brian for being great guy who sorted all paperwork, accepted me in team, explained everything and helped to understand some things when I was confused earlier.

Writing everything about me joining in Monochrome team isnt a great idea, as I dont want get into any details much.

DLC stuff.

Many of people already know information about:

  • Why our DLC got delayed. 
  • OST news.
  • Arrival of new programmer and more.
  • Futured list.
In case if some people missed this kind of information, please read this announcement.
I understand people cant really wait for DLC that longer, but please. Take a look at announcement, read it carefully. I also would like to ask people to keep an eye on forums. Who knows maybe there will be another discussion about DLC?

-Thanks and have fun.

Jan 13, 2015

Contagion: Melee weapons and how to be great with them.

Melee weapons are powered enough to wipe out the whole horde of zombies. And dont you even disagree with me on that one.

Logic by most players:

-Oh cool, I just found fire axe, lets kill some zombies with it. 
*attacking zombie with low stamina and hits zombie into the chest* 
*gets punched in face and gets infected* 
-Wow, these melee weapons sucks and I just got infected. Fuck them.
*throwing melee weapon away*
-I should also write negative review and\or complain about melee weapons on forums.

--Typical logic of most players I've seen so far.

So let me get things straight.

Melee weapons are powered enough to wipe out zombie horde, may come in handy against Riot police zombies and also, if you will use melee weapons perfectly you wont need any firearms in future. (The only exception might be is a player controlled zombies.) do I use melee weapon?

Hold on a little. You dont even know what you should remember first before even touching melee weapons.
  1. On HUD, you can see green bar.
    The green bar tells how much stamina you have. The more stamina - the better for you.
  2. Brainbox is the only thing that will truly kill AI\player controlled zombie while using melee weapon.
  3. Need stamina? You can recharge your stamina by either walking or standing still. Standing still recommended as it will recharge your stamina really quick, while walking will recharge your stamina slowly but in exchange you'll move away from AI that getting close to you.(Riot zombie for example.)
  4. Difficulty. The higher difficulty - the more health AI got(especially riot zombie.) and the more accurate hits in brainbox will require.
  5. Fireaxe\machete can be used to cut legs off from AI. Not recommended to do that so, but can be used if you need slow their movement a little.
  6. Mind yourself about ping.

Alright, cool. I got it. What now?

Lets take a look on types of melee weapons.

Currently there is 3 melee weapon types such as:
Sharp weapons: Fire axe;


Kabar knife.

Blunt weapons:


Baseball bat.

Objective item weapons: Fire extinguisher.(No kidding here.)

All of these (except of fire extinguisher) can kill zombies in one hit kill.
On Hard\Extreme difficulty, kabar knife would be useless for you, as most likely you'll need 2 hits to kill AI.
As for fire extinguisher; For me, its something useful if I dont have any melee weapons around.
On Normal difficulty 3 successful hits on AI kills em, 4 on Hard\Extreme difficulty(As video below shows.).


There is few strategies of attacking AI\player controlled zombie.

1: Early Beta's strategy. It is pretty much simple and easiest one to do.
Ensure you got full stamina, wait when AI\player controlled zombie is about to get close to you, tap right mouse button and hit AI\player controlled zombie in brainbox. AI\player controlled zombie dies, fall back a little if there is other AI near by and repeat the strategy.
Video. (Yet again google is being gay to me and refuses to show any uploaded videos on my youtube account, which is why I am leaving link.)

2: Charging strategy.
While this strategy may only work on blunt weapons, it is still possible to achieve kills with sharp weapons by using this strategy.
Hold right\left mouse button, get close to AI\player controlled zombie and hit it in brainbox. Fall back a little and repeat.

3: Sneaking behind AI zombie and silently kill them.
You can silently insta-kill AI zombies with this strategy.
To achieve this, you need to sneak behind zombie, ensure you'll see the icon allowing you to do insta-kill, press "V"(by default) and watch the insta-kill cam. It also works when AI zombies are chasing your fellow Survivor but be careful: some AI will switch target and will start attacking you instead.

The use of extinguisher melee attack is simple: Hit AI and fall back a little, then hit it again and fall back. Repeat this process until he die. Careful though, AI may simply raise his hands and smack you once upon time. (The reason why you dont want attack player controlled zombie with fire extinguisher is pretty much obvious.)

Riot police zombie encounter with melee attacks.

Aw yeah...a lot people still cant realize how weak Riot police zombie can be and instead of using melee attacks and play with his reaction, players perfers to shoot him in legs\head(doesnt really matter where you are shooting at.) and waste all ammo and then let themselfs die horribly.
If you got melee weapon, then it will be easier for you, as it will kill Riot police zombie much quicker.
If you dont have melee weapon, dont get sad, you still can play with his reaction and maybe once upon time you'll whack his head and he'll die.

Strategy.(Doesnt matter if you have melee or you dont.)

Riot police zombie chasing your fellow Survivor? Get close to Riot police zombie, hit him with melee attack and run away a little and see if he is chasing you now instead of your teammate. 
If he still chasing your teammate, hit him again, run away and check out if he is following you. 
If he is following you, keep running away from Riot police zombie until your fellow Survivor will hit him in back and Riot zombie will switch target to your fellow Survivor and start chasing him.
And just like that repeat the process until Riot police zombie die. It takes pretty much a lot time especially on Extreme difficulty but in exchange, you wont waste any bullets on Riot police zombie and you'll laugh how weak Riot police zombie is.

Striking Riot police zombie when its just you and him.

Strategy is simple: Hit and run. Better to have melee weapon for this case otherwise you'll spend a lot time taking him down.
Hit Riot police zombie in his helmet and run away from him. Recharge stamina and do it again.
Keep the distance while attacking Riot police zombie.
Use tables to prepare your strike against Riot police zombie. When he is climbing up to you, hit him in helmet and run away.

Additional notes.

Practice is the practice.
Be extremely careful when using melee weapon on higher difficulties. Wrong moves can either result in getting hit and get infected or killing innocently your fellow Survivor.
While attacking Riot police zombie, mind yourself about his attacks. He can easily slap you in face when he is faced to another direction. (Current bug with all AI zombies at this moment.)
Remember about your ping. Ping always tells you useful information.
Possibly...melee weapons will be balanced.

Point of this message today.

Complaining on forums\writing negative review about melee weapons being useless to you and\or not killing AI\player controlled zombies in one hit is just pathetic.
Learn how to use melee weapons. Do some research with it and you'll realize how melee weapons are powered enough, especially when you are working with fellow Survivor who also carrying melee weapon.

-Thanks and have fun.