First Person Shooter...
Lambda Wars is a free multiplayer Source Engine modification for Alien Swarm set in the Half-Life 2 universe that brings the war between mankind and their brutal Combine overlords to a traditional real-time strategy (RTS) setting. Lead the uprising as a commander of the Resistance or crush the rebellion as an overlord of the Combine, with both factions featuring a full host of units, abilities, buildings, research and defenses. Lambda Wars features full-fledged RTS gameplay and a robust RTS interface and is focused on multiplayer but strategic AI opponents and dedicated singleplayer missions are also included.
Previously known as Half-Life 2: Wars, Lambda Wars has been in steady development with a long history of acclaimed public alpha and beta releases since late 2007 and only requires Alien Swarm (free) installed on Steam to play. You also must legally own Half-Life 2: Episode Two.
Classic real-time strategy (RTS) gameplay in the Half-Life 2 world
Multiplayer support and game lobby including spectator mode
Wide variety of maps for up to 8 human or AI players
Play as either Combine or Resistance
Full unit tech tree that allows you to command everything from Manhacks to Striders
Full-fledged RTS interface and HUD with everything from minimap and fog of war to unit and production building groups
Build production and research facilities to requisition better units and unlock abilities and upgrades
Defensive structures, turrets and mines help defend your headquarters and vital resource points
Multiple game modes
Singleplayer missions, tutorial map and offline AI skirmish mode
Custom navigation code and deep Python integration - all unit and AI code is scripted in Python