Anybody remember the game 8 Eyes for the NES? I'm not sure if it qualifies as a guilty purchase, but it's basically a Castlevania rip-off.
It's a sidescrolling platformer, and you're this guy with a hawk, and you have to find these 8 jewels to Save the Land! The hawk was actually pretty cool, because it could be controlled by a 2nd player, and could clear out other platform levels before the fragile and vulnerable guy character had to climb a ladder and get his butt kicked by them. The bird only had one attack if I remember correctly - Dive - down+B or something... Man, that game was tough. But fun!