This game is a side scrolling shooter where you pilot a helicopter. The background is in a normal perspective but the helicopters are from a top down view. It looks weird but controls fine. The game play is very simple with few challenges.
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)