Loved it!
Once I started playing, I had to keep going until the end xD ! I thought the difficulty of this game was just right--yes you are going to die a lot, and sometimes, when you run into a wall right after finishing the "hard" part of the puzzle, it does get frustrating, but its that good kind of frustration that makes you want to try "just once more" for the 10th odd time.
I thought the graphics were superb--it had an artistic quality to it with simply the silhouettes, and you did a great job with the flapping of the crows wings.
I suppose my only complaint was that at some checkpoints, if you die you spawn back so low to the ground that if you don't immediately press the up button when you get back in, you touch the ground and are instantly dead again...but that is a minor issue that so long as you are paying attention and are quick really doesn't affect the game play that much.
Over all, I absolutely loved this!