Made of Hard and Win
Ever played a little gem called "I Wanna Be The Guy"? While this game isn't quite THAT hard, it's certainly incredibly challenging. Lucky you I like challenging games. :) I very much enjoyed the fast paced story and unique gameplay mechanics.
There were a couple glitches that detracted from the game... namely on the third boss (who is, by the way, MUCH harder than the final boss, might want to do something about that) sometimes the screen flashes and you instantly die after beating her. Happened to me about five times, and was annoying.
Overall, though, while not the best choice for the average "Games are about the magical experience!" gamer, those of us who prefer our games to kick us in the nuts a few times while we desperately struggle for every single checkpoint (Megaman 9? :p ) will enjoy this game.