Decay

for Half-Life

24th September 2008

Half-Life: Decay is an add-on included in the PlayStation 2 port of the first-person shooter computer game Half-Life, developed by Gearbox Software and published in October of 2001, and has now been released as a mod for PC by independent Ukrainian developers along with the help of other European developers/fans.

The team has created a straight port of this game to PC and started active development in mid-October of 2005.

Like Gearbox’s other expansion packs, Opposing Force and Blue Shift, Decay returns to the setting and timeline of the original story, but with different player characters: two female colleagues of Gordon Freeman, Dr. Gina Cross and Dr. Colette Green, who both take part in the Anomalous Materials laboratory experiment – they make preparations for the experiment under the Test Chamber such as monitoring Anti-Mass spectrometer and delivering anomalous materials to Dr. Freeman. When disaster happens both women, together with their colleagues Dr. Rosenberg and Dr. Keller, try to save personell of the facility and reverse the resonance cascade to seal the dimensional rift.

Unlike other games in the series Decay is a cooperative game and its storyline is divided into “chapters”. You must play through the whole game with both Gina and Colette, you can switch between them when in SP mode, though AI controlled bot won’t follow you and will only shoot the enemies. However various puzzles and combat situations throughout the game require the co-operation of the two characters.

Also Decay has a ranking system for all of its nine missions, ranging from F (worst) to A (best), based on accuracy, number of enemies killed, and damage taken. If all nine missions are achieved with an A level, a bonus mission, Xen Attacks, can be played as a pair of Vortigaunts.

Decay opens both new and old areas of Black Mesa research facility, such as Gamma labs and Training Facility.

Basic Details
  • Title: Decay
  • File Name: hl1-sp-decay.7z
  • Original File Name: decay_eng.exe
  • Size : 34.8MB
  • Author: Decay Team
  • Date Released: 23 September 2008

Download Options

Download to your HDD [3.18MB]
You can still use it with MapTap once you have downloaded it.

Important Note

Whilst this mod can be described as single player it requires you to control two characters at once and you must switch between the two.

When setting your key assignments DO NOT assign the G key because this is needed to switch characters and there is no way (That I can see) to change this. I had to reinstall the mod after I found this out.

IMPORTANT UPDATE FOR WON USERS:
Download this file and put into Half-Life\Decay folder. To start playing Decay select Multiplayer and create new LAN server for DY_ACCIDENT1 map

Steam Installation Instructions
  • Copy the decay folder into your …\Steam\SteamApps\common\Half-Life folder.
  • Restart or start Steam.
  • Decay should now be listed in your Library tab.

Videos

Screenshots

Click on the thumbnails below to open a 1024 pixel wide image.
WARNING: The screenshots may contain spoilers.

Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
How To Get The Bonus Mission

Reader Recommendations
Avoid It!
Think Twice
Maybe
Play It Later
Play It Now!

16 recommendations, average score: 4.5 (out of 5), standard deviation: 0.5 (what's that?)
Total Downloads

Please note: These statistics are valid from December 2010

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Meta Review Data
Statistics based on 2 comment(s) with meta review data.

Installed:
Using Gauge: Users
Manually: 2 Users

Time Taken:
Average: 4 Hours, 40 Mins
Shortest: 4 Hours, 30 Mins by Handsome-Shrek
Longest: 4 Hours, 50 Mins by Angel_of_Death02
Total Time Played: 9 Hours, 20 Mins
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40 Comments

  1. Before you start playing you should be aware of a very important gameplay mechanic and that is the need, yes NEED, to switch between two playing characters.

    Ultimately I found this too annoying, especially since the characters twist when you leave them making returning to them a little disorientating. I therefore have stopped playing and won’t play any more.

    However, that’s just a personal opinion and it’s clear that the quality of this mod is definitely worth a Play It Now! recommendation.

    I was so disappointed that it couldn’t be a true SP experience becasue I am sure it would have ranked in the top 5 of most players favourites.

    I have nothing but admiration for the team, congratulations by the way, and wish that more mod too this much care and attention to detail.

    Go play it now and see how you feel about the switching.

  2. galocza

    RELEASED AT LAST!
    thanks!

  3. Ashkandi

    Good, but I cant make any servers, so I nead dedicated :3

  4. darkstranger

    finally

  5. Marc Wirachowsky

    Which correct path did you choose for your installation planetphillip? My path for Hl Won is: C:\GAMES\Half-Life

    So I guess from your instructions planetphillip

    You install MOD

    Launch HL and select MP and it should be in the main MP menu.

  6. tox

    It’s not easy, all serious…

  7. Which correct path did you choose for your installation planetphillip?

    I don’t have a WON installation, it’s Steam but I am guessing it’s the same for all Half-Life 1 mods you have installed. It created its own folder in my installation, so again, I presume it will do the same for WON installations.

  8. There is an update available for WON users. Please see the main post.

  9. Awesome! I have always wanted to play this, but I never had a Playstation.

  10. 23-down
    Play It Now!

    It’s a fantastic mod! I played alone till level 5. But you really should play it with another human in your team.

    Because it’s hard sometimes to protect both players at the same time. So I failed for the first time on level 5. Go and play it now it’s an official part of the storyline that means if you count the gearbox games as cannon. At least I do so.

  11. Zombie-Hunter

    Believe it or not, I found this mod easy to play with a gamepad.

  12. Count_de_Monet

    It looks great but I’m stuck at the very beginning, at registration. I can’t go through. Any hint?

    C de M

  13. AI

    Do you have to use both of the characters to play this?? Gets very confusing at which way to go!!

  14. Yes you need both as some parts require 2 persons to complete some parts but with some area’s you can actually go far without using the other

  15. Stuck at registration?Not sure where that is but you need to go in a scanner(both people seperatly) and go see the scientists down the hall after.

  16. ~Jazz~
    Maybe?

    I never played Decay for the PS2, I did learn that the entire time your going to be controlling 2 flat chested woman for a very long and annoying time. Wait a minute, instead of making one of the chars a NPC they made it player controlled? did valve take some pills from underneath there parents sink? Most likely, Well lets hope this port they don’t do the same thing, I mean that would totally.. oh shit they did. I can’t even get a server going or join one for that matter, since there seems to be a very needed LEVELCHANGE at the end of the outro map. If your not watching your server, you will get very pissed off players saying “HEY, there’s nothing but blackness.. this sucks” Well it dose when you have 5.. That’s right 5 servers with outro stuck on them. Also, I’d like to add that having your name changed to some flat chested, hev suit wearing, scientist woman .. IS.. and will always be.. ANNOYING. I don’t care if there names are Gina and Colette, I want my name. My Name is ~Jazz~ not Gina. I got so annoyed by that I binded a button to change my name every time It was forced. Overall, it’s nice to see that it’s out.. I mean I had a ton of people going ape shit when it was released the first hour, but it’s not the best in the world.. Is it worth playing? Well if you have a mate and your both downloading porn and need an hour to kill I wouldn’t say not to play this mod.. That’s all It is, A good time waster with mutiplayer support.. I hope someone puts this on Sven coop someday.. now THAT would be BAD ASS..

  17. Greenhorn
    Play It Later

    It is possible to turn your other character by walking in front of them so they can face an appropriate direction. It is frustrating to have to do so at times but I don’t think it was possible to have it work like it should.

    I have been eagerly awaiting the port of Decay from the first time I heard of it. It can be frustrating to have to replay the entire level, especially when death comes from the poor bot/NPC AI. For myself, and the many other HL fans that don’t own a PS2, this release fills a void that Valve should have filled long ago. While not the best chapter in the HL universe it is certainly well worth playing, especially with another person controlling your partner.

  18. MASTER74
    Play It Now!

    This mod is great, especially if you play it on-line with another person. Anyway, playing HL: Decay “off-line” with a bot is quite entertaining as well, you can get to know maps and game mechanics before you go playing co-op with another human on-line.
    Furthermore, HL: Decay is part of the official story (as someone already said), so it’s definitely worth playing 🙂

  19. I play with a WON version and I have some trouble: my two characters haves the same face (but different suit), It is normal?

  20. I believe they are the same models with just a different colour suit so it’s normal.Different color so you know who is who I guess lol.

  21. Ok fixed, I just reinstall the game and now I have two different models like in screenshots. I believe that it’s because I don’t put the liblist file for WON user at first. Thanks for answer andyb

  22. Maybe I should of looked at the screen shots myself lol.They do indeed have different face/hair.I’ve played to many mods lately and forget what I’m talking about.

  23. Darth Marsden
    Play It Later

    As a single player, I’ve found this quite fun, if hard in places. The only major issue I’ve found (aside from switching back to my other character to find I’m under attack!) is the aforementioned ‘twisting’, in which the bot doesn’t face the same direction you leave it in. If you’re switching quite rapidly, this can be very frustrating!

    Otherwise, a great product and I’d recommend it. No idea how it works multiplayer-wise, but I’d imagine it being a lot more fun!

  24. fadi
    Play It Now!

    IT IS THE BEST MOD EVER CREATED I DON’t KNOW THE PC VERSION BUT I PLAYED IT ON PS2 I DOWNLOADED IT TODAY ITS THE SAME AND THE WEAPONS GRAFICS SKINS MODELS ARE GREAT AND THE SOUNDS ARE ORIGINAL GOOD JOB

    ps:its made by gearbox,valve and sierra

  25. KingDaniel
    Play It Now!

    I love this. No saving in SP is evil, but makes it ultra-tense.
    However, i’m stuck on the (last?) level.
    ***possible spoiler***
    Dr. Keller warns me that i’ll fight “more enemies than i’ve ever seen before”, and have to do something with crystals. I send both characters outside to the big array thing, but nothing happens. There are what look like levers on boxes in the rock walls, but they don’t work. Nothing happens.
    What am I missing?

  26. I’m on the map in the dormitories, at the end when I lead the security guard to doctor Keller he don’t react. There is something else to do?

  27. Leo(T.C.K.)
    Play It Now!

    Dy_dorms have that bug, you must not use the security guard, in fact you must follow him, so don’t use use key, it will be fixed in next version, this is a bug. If you follow him and don’t interrupt him everything will be fine.
    This mod is great, but it’s much more fun in multiplayer, but there is lack of servers and only 2 players are possible per game, which is sad.

  28. Thanks Leo this is a stupid bug but he stuck me during one week

  29. Play It Now!

    Amazing how that been ripped to Steam. DECAY is a great addition to any HL fan. Good news that it can be played both SP or MP, all in the Black Mesa areas already known with that classical HL1 design. Can’t rate it differently because I love BM themed mods and this was originally a Gearbox game, kudos to the ucranian who put this up and the devteam.

  30. your evil twin
    Play It Now!

    This is a fantastic recreation of the PS2 game, with both the same pros and cons. Basically, this game is designed for multiplayer, and is approximately 200% more fun with another person. Singleplayer is for any unfortunate people that have no friends, but swapping between characters to get things done isn’t much fun.

    Team up with another friend with Half-Life, both go on Skype or some other voice-chat service, then play through Decay together. The PC version is slightly easier than the PS2 version, thanks to it being easier to aim with a mouse than a PS2 controller. This doesn’t change the fact that you really do have to work together and cover each other and not do anything stupid, because if one of you dies it is game over for both of you and you have to restart the level. This makes the game far more tense than other cooperative games where you repawn, and more tense than singleplayer games where you can save and load.

    Oh, and for anyone wondering how the ending can possibly be compatible with Half-Life 2 and the portal storms etc… bear in mind that without the resonance reversal, the dimensional rift would have gotten larger and larger until the whole world was covered in one gigantic dimensional rift, a continuous 24/7 portal storm forever. Thanks to Gina, Collete and Dr Keller the world of Half-Life 2 only had to contend with the occasional portal storm emerging from the Black Mesa area, travelling aross the world like weather systems. So yeah, there you go, this game can still be considered an official part of the storyline, it doesn’t contradict the Half-Life 2 story. Gotta give credit to Gearbox for adding to the Half-Life story without screwing it up!

  31. poisonheadcrab
    Play It Later

    A must play by far (when playing with another person ofcourse). The only problem I have is that it is too short.

  32. rafar

    Hello … the singleplayer mode is a character only??…and I am stuck at the gate of access after my identity … and the multiplayer mode .. there are two doctors, but can not save the game .. do you think help .. thanks.

  33. Andrew37

    hey plz help im stuck at the menu, the game begins but then seconds later crashes and the game finish… plz help :S

  34. Killer010793

    Is there anyway to get this to work with Half-Life Source?

  35. Play It Now!

    With Lands of Loria this is one of those mods, that can be played in multiplayer mode as singleplayer. I like this mod, although it not so long, as I want. Interesting gameplay and storyline “Cross”ed with Half-Life 🙂 Cool! And today I found on Youtube a solution how to get work some hidden features of this mod. So I really need to replay it.

  36. Personal Favourite

    This is a personal favorite of mine simply because there is NO other game that demands actual team work and planning to get through the way this game does.(Actually Zelda 4 Swords Adventure has a very similar teamwork method, but it doesn’t support online Multiplayer) You have to talk to each other and plan out what you’ll be doing, and occasionally a player has to be stranded away from the main action in order to open up a temporary route to allow the other player to progress through the game and then come back to pick up the stranded player after they’ve opened up the way permanently.

    There is a bonus level that is unlocked by both players getting rank A on all regular levels, however I’ve found that this tends to be VERY difficult (both players practically need max health and suit power and to never miss while shooting) which severely strains friendly relations with your partner.
    Phillip has recently embedded a video that demonstrates how to unlock this bonus mission with minimal effort, but just in case the video ever gets taken down, just do a search for “unlock Dy_alien Decay” and one of the first results will likely give you the instructions you need. Once you follow them, you can relax and just concentrate on playing together and surviving each level.

    LAN play is the easiest way to get a game going together, as you only need to both be running the game and be on the same router, but it only works if you can both be in the same room while playing.
    Online play is possible, but it requires one of the players to have set up Dedicated Server properly for the other person to connect to. (Dedicated Server is under the Tools Tab in the steam browser)
    In order to set Decay up to run on Dedicated Server you need to manually copy your decay folder from the half-life folder and paste it into the dedicated server folder. After that, you will probably need to go into the decay folder that is in the dedicated server folder and create a blank text file titled “steam_appid.txt” (without quotes) and then open that file and type in “70” (again, without quotes) before saving and closing it. When you run Dedicated server, you will need to set the Game to “Decay”, set the Max. players to 3(not 2), set the Network to “Internet”, and set the Map to one of the maps that you’ve already unlocked.
    Once you have Decay running on the dedicated server, you will need to run the actual Decay mod and then connect to the dedicated server in the lan servers section. Whoever wants to play with you and connect from online will then need to look for your server in the online servers section.
    The maps that are available to you on the Dedicated Server will depend on any progress you made before copying your decay folder to the Dedicated server folder, and then after that will depend entirely on the progress you make ON dedicated server, and not the progress you make playing a local game. Only the person hosting the game will have their progress and unlocked levels saved, the person joining the game will not have any of the progress they make apply to their own game.

    This isn’t a really fun single player game, and needing to restart the level if even just one person dies, especially with no saves, can make for a frustratingly brutal coop game too, but basically it all boils down to finding someone who is decent at half life that you can work well with (and not sucking at it yourself) Once you meet those requirements, you’ll be downright golden, and perhaps one of the best Half Life experiences you’ve ever played.

  37. Maybe?

    Frustrating, buggy and unclear in places, but if you feel like playing every official Half-life release, then it won’t disappoint any more than Blue Shift. Be sure to grab a friend as playing alone and switching characters is just not the way to go.

  38. m3rlz

    When setting your key assignments DO NOT assign the G key because this is needed to switch characters and there is no way (That I can see) to change this. I had to reinstall the mod after I found this out.

    bind ANYKEY changeplayer

    haven’t played this mod in a long time; awesome mod. \m/

  39. Play It Later

    This mod is essentially a PC port of the Half life expansion by the same name which was released for the ps2. If you are a Half Life fan i see no reason not to play this mod since for the most part the gameplay is the same as Half Life and its expansions.

  40. Personal Favourite

    HEADER:

    Flawed Diamond

    Excellent port, and as for the game itself, i love it.

    It may not be the most depurated co-op experience, heck, it may not even be up to the standards of another co-op MODS (noting that this was a retail product on release), but it’s still damn fun.

    It’s an incredible experience, and if you’re into HL canon this one is a real treat. Voice acting is excellent and it’s long but short enough to play it in one sitting with a buddy.

    As a game (and with this i refer the original retail product) i give it a 7/10, but as a port of a PS2- only game with such stability and the option to let you play solo or online it’s worthy of a 10/10.

    Go now and play this flawed and underappreciated gem.

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