What originally started out as a joke project, and then became a serious game as time went on. Castlevania, arcade style, with sprites from Maplestory! Includes 3 characters. Comes with PSP OpenBOR version to play it with.
I don't have a wii u anymore to test it myself, but if homebrews are not visible on the wii u menu I think you can press L + R + minus to open the plugin menu, there should be an option called "homebrews on wii u menu" or something similar
Or when your player dies, you can say in code, if enemy exists, do nothing, but if enemy does not exist, then create enemy at certain spot. (This would be a pain tho for lots of emeies)