: While it is technically a mod, you do not need to have Half-Life 2 or Alien Swarm installed to play it; Steam will automatically handle any necessary engine files.
: Simply click the "Install" button on the Steam store page to add it to your library and begin the download. Key Gameplay Features Lambda wars Download PC Game
: Engage in 4v4 multiplayer matches, offline skirmishes against AI, single-player missions, or an "Endless Wave" survival mode. : While it is technically a mod, you
Because it uses a branch of the Source Engine, the game is highly accessible for most modern and even older PCs: offline skirmishes against AI