Awesome game... Part tetris, part donkey kong... You have to use your brain to solve the puzzles (sometimes quickly) to get the stars, and have to hit fiendishly-precise button combinations/timings to set a fast time (or even get through the level sometimes)...
This kept me thoroughly hooked, and as of this writing, I have all the stars and sit at #6 on the all-time high scores list...
(All I have to say about "much blood!!!" is: YOU BASTARD! THAT ONE TOOK ME LIKE AN HOUR!!! Lol)
There are a couple of niggling things that I don't really consider "drawbacks" as such, but little refinements you might make if you made a commercial version of this game (which I'm sure you could):
1) I remember the controls being a little loopy on a couple of occasions, but I really couldn't tell you how or where, since I was so sucked into trying to beat my high score/get all the stars...
2) Sometimes you can fall from a "crumbling" square, and still get pegged by the spike squares in the row/column beside it. Maybe try making it so that it auto-centres you on the square whenever you land on a "crumbling" square.
3) This last one is a problem in like 9/10 games that have spikes in them, but when you hit the /side/ of the spikes, you die. This just doesn't make any sense at all to me...