How about a game where you add and modify and mess with weaponry and weapon attachments, being a trippy platformer, creating and destroying your world, and there would be three chapters, the north korea part where you have to escape, 6 hour-week full game for the second part with horror elements being within a school.
all the ideas mixed together with a new suggestion to help originality, make it a touhou like bullet hell on top
Edit: forgot the big bang part as the third part
E2: Action RPG elements and the school is within NYC