When I was like 10 or 11 years old, I wrote this gigantic game design document over the course of a few months. The premise of the game was that it started off as a 2D platformer, but as you progressed through the game, the genres would start changing. There were thematic reasons why you’d go from something like a 3D action adventure to a puzzle game, to rhythm, to RTS, etc. It was sort of like a WarioWare game, only each genre would last 5-30 minutes, instead of 5-30 seconds, and they would be loosely connected through a story and characters.
Needless to say, it was an incredibly ambitious idea, since it basically was a game made of complete vertical slices of dozens of game genres. Once I started getting more serious into game dev and went to college for it, I realized this was a completely unrealistic project at the time, since it meant I’d have to personally perfect just about every game genre out there.
Nowadays, it’s a bit less of a stretch, since there are so many incredible pre-built gameplay engines for just about every genre inside of Unity, UE, and even GMS. Maybe someday I’ll return back to that concept. Though my coding chips have declined significantly over the last decade.