80's power ballads.
Imagine a SHMUP where each level is themed after a particular 80's power ballad.
You could have stuff like The Final Countdown which is all about running to escape a ship on its way to Venus about to self-destruct.
You could have a level based on Rock You Like A Hurricane, where you have to fly through airborne debris during a hurricane to rescue people.
You could have a level based on Take On Me which is all done in that hand-drawn pencil shit from the film clip, and it's a brawler like Double Dragon.
I imagine it like an 80's mixtape themed high-score chaser crossed with Wario Ware.