So Dustforce. It's a time/score attack precision platformer where you sweep up all of the dust and get to the end of the level as fast as possible. I'm glad I'm not joking.
Rochard is a physics-based platformer which relies a whole lot on gravity manipulation. You can manipulate gravity of the area, and you also have a gravity gun to solve puzzles with. You also get some guns, grenades, and so on for some light combat elements and more explosive puzzle solving.
Shatter is a breakout clone which relies on being very physics-based. Some blocks will move about according to the physics engine, and you have a fan that can pull in or blow away various objects, including the ball itself.
Space Pirates And Zombies is a game that's all about going around in space, being a pirate, stealing or trading for blueprints, and getting your mothership as powerful as possible. Later on, zombies are introduced and the game establishes sort of a meta-campaign where you push back zombie territory to fix up regular space society.
Torchlight is... sod it, you know what Torchlight is.
And, Vessel is a puzzle platformer with neato water physics, and the ability to create little buddies out of water who will help you solve puzzles.