simplicity isn't bad
why do you think complexity is required for something to be fun
platformers are typically simplistic but are given depth and interest through the use of clever level design (which doesn't remove from the simplicity, it just causes you to apply the simple mechanics you know differently), and this captures that spirit very well
incidentally too much complexity could cause the game to be a clusterforget. i mean, if you were required to have an intricate knowledge of every key on your keyboard and the various functions they all performed you would never progress in the first place (unless it was a typing game, in which case it flips right back into simplicity)
