I played through a flash game last night called Coma. I played it on the popular flash gaming site Newgrounds.
Coma is a 2D atmospheric platformer with light puzzle elements. What I mean by light puzzle elements is that the game has puzzles but they're not very hard to figure out and the game is more about the journey then solving puzzles.
As I was playing Coma I couldn't help but be reminded of the art style of Limbo. Coma even makes reference to finding a sister and I'm wondering if that's a reference to Limbo.
Coma controls really well with a floaty jump mechanic that works for this game. The visuals and music are really well done not just for a flash game but it stands up with some full retail games.
If you have a spare 15-20 minutes you should check out Coma.