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Alien Swarm: Steam's Free Hit Release

by: J. Edward Casteele ; edited by: Michael Hartman ; updated: 4/17/2012 • Leave a comment

Valve's Alien Swarm was released in July 2010 as a free game on Steam. The Valve Alien Swarm game is based on the popular Unreal Tournament mod of the same name, and was ported to the Source engine by the mods creators. The game became an overnight success, becoming the most played game on Steam.

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    Alien Swarm

    Alien Swarm is a free Source Engine game on Steam.   Capturing much of the feel of the Aliens movie franchise, Valve's Alien Swarm game puts players in the heart of a space colony that has been overrun by alien monsters. This 4-player top down co-op game features frantic action, an immersive environment full of danger, and enough ranks perks and achievements to keep casual and hardcore players alike interested. The game became an overnight sensation, and it's no wonder; when Valve released Alien Swarm on Steam they did so as a free game with a full set of mod tools available for players to expand on as they see fit.

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    History of the Game

    Alien Swarm features class based coop gameplay updated from the original mod.   Valve's Alien Swarm began life as a mod for Unreal Tournament, garnering enough attention from the gaming community that Valve extended job offers to the mod's creators. Coming on board to work on popular games such as the Left 4 Dead series, Valve also asked them to begin working on a Source Engine port of their popular mod behind closed doors. The game was intended for release as a co-op experience true to the original mod, making it significantly different than the other first-person shooters that had been released on Source. To stay close to the nature of the mod, Valve planned to release Alien Swarm on Steam for free so that fans of the original and those who had never played it before could both enjoy the new Alien Swarm without having to pay a cent.

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    Free Release on Steam

    Tens of thousands of players were online within hours of the game release.   Alien Swarm was released on July 19, 2010, on Valve's Steam platform as a free download. Within a day it was the most played game on Steam, with nearly 60,500 players online during the game's peak on July 20th. The original release time was pushed back by two hours, possibly in an effort to prepare the download servers for what was sure to be a massive load; once the game was released, however, the Steam servers nearly buckled under the strain. There weren't enough download slots available for the mass of people attempting to download Alien Swarm on Steam, and a number of fans reported slow download speeds when they were able to start the download at all. Despite this, there were few serious complaints; the biggest complaint seemed to be that the players would have to wait longer before they had a chance to play the game.

    Once the game was released, Valve switched immediately to support mode. Within a few days they had already released two patches to fix the most glaring problems and were active in the fan communities to find out what else needed to be fixed. Despite the free nature of the game, it was obvious that Valve's Alien Swarm was getting the same level of support that they would offer for any of their paid game products.

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    Alien Swarm Gameplay

    Puzzles and strategy are an important part of Alien Swarm gameplay.   Valve's Alien Swarm features a number of interesting gameplay features that set it apart from other Source Engine games. In addition to being a top down shooter, elements such as puzzles (used by the team tech expert to hack into colony computer systems) and synchronized slow motion for all four players helped to give the game its unique feel. There are a number of interactions that players can have with the game environment, including welding doors shut to slow down the alien hordes (and being killed by those same doors if they're too close when the aliens finally bring them down), and the alien menace that the players much face comes in a number of deadly varieties. Players can even become infested with alien parasites, causing them to burst open if they aren't healed in time and spawning additional parasites for the other players to face in the process.

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    Steam Achievements

    The Alien Swarm Parasite hat can be equipped by any Team Fortress 2 class.   As with all Source Engine games, Valve's Alien Swarm was released with a number of Steam Achievements. The game was released with 64 Steam Achievements available, presenting a wide range of achievements with varied difficulty levels. Some achievements such as "Technician Secured" and "Zero Mortality" rely on players making it through levels with certain party members still alive, while achievements such as the "Speed Run" series involve players completing levels within a certain timeframe. Achievements such as "Another Bug Hunt" and "Nuke from Orbit" are awarded based on the total number of aliens that a player has killed, with other achievements such as "Professional Marksman" and "Minigun Master" being awarded based on the number of aliens killed with specific weapons. One achievement even rewards the player in a completely different game; those who earn the "Hat Trick" achievement for completing two co-op missions online when playing Alien Swarm on Steam will also be given a "Swarm Parasite" hat in Valve's Source Engine game Team Fortress 2.

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    Map Creation and Modding

    Alien Swarm features a built in tile based map editor.   Like all games on the Source engine, Valve's Alien Swarm makes use of the Source Software Development Kit (SDK) to allow modding and the creation of custom maps. Alien Swarm takes map and mod support a step further, however, including a second map editor within the game itself. The second editor is tile-based, making it significantly easier to use than the Hammer world editor that is used to make maps for other Source engine games. All that a user has to do is create a map with the tile-based editor and the compiler will automatically add enemies and any specified objectives to the game without the fear of errors or players falling through "holes" in the map world.

    Accessing the tile-based map editor in Alien Swarm on Steam is easy. The in-game console must first be enabled by checking the box at the bottom of the "Keyboard and Control" options menu. Once enabled, access the console by pressing the "~" key (though this key can be changed in the key bindings section of the "Keyboard and Control" menu.) Once the console is open, type "sv_cheats 1" and press the "Enter" key on your keyboard to enable in-game cheat functions which are required to activate the editor. Type "asw_tilegen" and press "Enter" to launch the editor, then drag-and-drop tiles to create a map. Finished maps can be opened in the Hammer map editor for tweaking and exporting for distribution to other players.