Its based on an old computer game from BreadHill software.The objective is to find the keys then get to the exit. You will encounter a monsterevery couple of steps you take. If you pass the monster's challenge, you can move on.
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)