it's really good musically, the concept is great, the graphics are really well built, but the levels? no thanks. poor, uninspired, almost pointless use of keys, doors, ladders and enemies. the time mechanic could work if it weren't so bloody repetitive, unrelenting in it's use of keys and the order you use them.
also, games in which you are given NO clues as to how the level is supposed to be completed give me no fun at all. none. it's probably why i enjoy Sonic the Hedgehog more than the little bent plumber, huh.