Has anyone ever played any castlevania games? In every one of them is a clock tower level full of flying enemies, a load of platform jumping, and spikes and other prince of persia-like traps on every available surface twice over. In the later ones where there are some RPG elements, I remember spending hours grinding on the enemies in some of the simpler rooms so I could get enough health to get through in if not one piece, at least a relatively low number of pieces.