Lambda Wars (formerly Half-Life 2: Wars) brings the struggle between the human resistance and their Combine overlords to a multiplayer real-time strategy setting. The Lambda Wars beta only requires Alien Swarm installed to play. It features 3 multiplayer game modes: Sandbox, Annihilation and Overrun, showcasing the Rebels and Combine playable factions and a full-fledged RTS interface and HUD. There is also a singleplayer tutorial and a handful of singleplayer missions.
In the next version 2.2.0, units will support following other units (something that was still missing). When in follow mode, units will attack any enemies along the following unit.
The video also shows the new cover particle effects, shown when hovering the mouse around cover spots.