Alien Swarm – A Top-Down Open-Source Shooter By Valve

Simon Slangen 27-07-2010

shooter gameA lot of die-hard gamers might have heard of the Alien Swarm shooter game in the past. The game originated as a full-conversion mod for the popular arena shooter Unreal Tournament 2004; completely developed by a score of community developers.


Those same developers were subsequently hired by Valve, the top game publisher that’s behind Half Life 2 and Team Fortress 2. While working on projects like Left 4 Dead 2 and Portal 2, in the background they were rebuilding their debut shooter game from scratch.

Alien Swarm

Steam (Valve’s gaming network) just recently revealed the existence of that remake, mere days before the game launched last Monday. But the accompanying news was even more shocking. This fully-featured game would be released for free.

What can you expect? Think swarms upon swarms of magnificently brutal aliens and empowering online (co-operative) gameplay. There’s not all that much of a story, just fast-packed shoot-em-up levels. This is a game you should play this summer – no matter if you’re usually a freeware or retail gamer. The only detectable downside is that this shooter game is only available on Windows PC’s.

4 Player Co-Op Killing Spree

Alien Swarm offers two modes of gameplay; the less important offline training mode and the online campaign mode. Up to four players can join up to compete and join hands against the alien horde. In that, it’s very similar to Left 4 Dead (2). In other things, not so much. There’s bound to be less randomization in the levels, in a way enabling you to learn from failed experiences, and develop tactics to beat the levels.


shooter game

How difficult those levels will be is entirely up to you. Alien Swarm offers 4 degrees of difficulty; Easy, Normal, Hard and Insane. You’ll be assisted in your post-modern quest by over 40 different weapons, with an absurd amount of additional weapon configurations and other unlockable items.

shooter games

There are in total four unique IAF (interstellar armed forces) player classes to choose from: medic, tech, officer and special weapons. And each of those feature two different characters. Create an IAF squad with your friends and make those aliens regret they got up in the morning.


Free, Open-Source & With Separate SDK

Actually, Steam didn’t just announce the game to be free. Yes, you can download the game free of charge. But you can also download the entire source code. This is unprecedented for a major game company like Valve, and rocked the socks off of large parts of the internet. This means that everyone can view the original programming that went into make this game. Everyone can adapt the code, and make spin-offs.

shooter game

Although the game launched with 7 ‘official’ levels, you can also download a level creation kit. For those interested, this is not the standard kit that you’ll see included with other Valve games, but a stand-alone one. This includes a tile-based map generation tool, allowing you to randomly generate rooms in your home-brewed levels.

Are you excited yet? That’s right! What do you think of Alien Swarm, or it going open-source from day one? Let us know in the comments!


Related topics: First Person Shooter, Multiplayer Games.

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  1. hocsinh
    August 10, 2010 at 9:07 am

    thanks for infor. very interesting post

  2. Kevin
    July 28, 2010 at 9:37 pm

    According to /. you can easily convert AS to a FPS game instead a top down shooter.

  3. Kevin
    July 28, 2010 at 7:37 pm

    According to /. you can easily convert AS to a FPS game instead a top down shooter.

    • Simon Slangen
      July 29, 2010 at 10:29 am

      Awesome, thanks for the tip!

  4. Hello
    July 28, 2010 at 9:23 pm

    Too bad, you need to install Steam to play :(
    Thanks, bot NO thnaks!

  5. Hello
    July 28, 2010 at 7:23 pm

    Too bad, you need to install Steam to play :(
    Thanks, bot NO thnaks!

  6. Srivatsan Venkatesh
    July 28, 2010 at 3:07 pm

    I got it. Some person said he got it running on his netbook but mine is a nogo. I have 1g memory and a 1.6 Ghz Atom. Help? Maybe I have too much stuff running.

  7. 098
    July 28, 2010 at 11:15 am

    It seems to me you cannot install or download this game without the Steam parasite-ware installed on your PC first. NOT GOOD. or am i wrong...

    • Simon Slangen
      July 28, 2010 at 1:35 pm

      Steam's store/game library (an excellent gaming application, might I add) is a 1.5MB download, and it allows you to download a free, full feature game. Parasites? I beg to differ.

      • Joseph Schwenker
        October 3, 2010 at 8:42 pm

        I remember in the days of dial-up, 1 MB took about fifteen minutes to download. If this game is open source, then you should be able to play it without Steam, which, in this case, only serves to advertise and take up CPU usage.

  8. IshootPeople
    July 28, 2010 at 6:24 am

    nice :) flamethrower just got my heart

  9. Anonymous
    July 27, 2010 at 10:57 pm

    Started playing the other day, great game!

  10. William Brand
    July 27, 2010 at 8:29 pm

    Very fun game :) My SteamID is Willtastic if anyone wants to add me and play.

  11. Johnm
    July 27, 2010 at 7:57 pm

    It's not open source... There is an SDK, but it's not open source.

    • Simon Slangen
      July 27, 2010 at 8:28 pm

      No, it's definitely open-source. From the site: "Along with the game get the complete code base for Alien Swarm that features updates to the Source engine as well as the SDK." :-)

    • William Brand
      July 27, 2010 at 8:28 pm

      Well, along with the SDK they released the source code for the entire game. How do you define open source?