Team Fortress 2

Team Fortress® 2 (TF2) is the sequel to the game that put class-based, multiplayer team warfare on the map.

Play as the flame-throwing Pyro, the room clearing Heavy, or the Spy, a master of disguises. Other classes include: Scout, Sniper, Medic, Engineer, Demoman, or Soldier.
Pre-purchase the "everything explained in the title" game Mount & Blade With Fire & Sword by May 3rd and you'll receive two new TF2 hats: The Hetman's Headpiece for the Engineer, and the Janissary Ketche for the Spy, pictured above.

What else is up? This: SpaceChem, the game Robin Walker dubbed "pretty much the greatest game ever made," has introduced three new TF2-themed levels. Travel to Australia, solve puzzles and unlock achievements to receive the new craftable element Moustachium in TF2. Use this new element to craft special SpaceChem-themed items, including a fishcake. That's right: this marks the start of a trend we're all for: other developer working their butts off to make a promotion for us. "Put your feet up, Team Fortress Team," SpaceChem seems to be saying. "You let us handle this one." Don't mind if we do, SpaceChem.