I don't usually play platformers, but when I do, I play Super Meat Boy.
I really can't think of a complaint. It's a solid game, with a solid premise, and it's hard which I don't think is a bad thing. It seems the trend these days is to make games easy enough to beat but then they lose the satisfaction of completing them. Super Meat Boy brings back that sense of accomplishment especially if you are a spurgelorg and manage to beat all of the dark levels and bandages.
If you've grown tired of easy platformers like Mario Galaxy 2, try your hands on this game. The best part is that if you acquire enough bandages in the game, you unlock new characters with unique abilities which may or may not make the game easier. It really depends on how you use them.
One interesting detail about the game I liked was that most of the really hard levels are more of a puzzle-solving exercise than a skill with dexterity. Sometimes just reading the level and thinking about it makes all the difference rather than just running through and hoping for the best. All of the levels basically have a best path that if followed with the right timing will allow to basically run through the level with ease.
Hopefully this developer will produce more unique games. Buy it!