A platformer game where all platforms are split into these rectangular chunks, which you activate/power-up/change by touching them.
The main objective of the game is NOT to reach a specific place, but to simply touch all these chunks in a level. Stay alive until you did so, until you “painted” all the (right) platforms.
A Related Idea
A snake-like game where your goal is to paint the entire area. (You can probably just go through your own tail, it’s not really about that.)
Monsters come at you from the sides (like asteroids and hack-n-slashes and roguelites and stuff)
You must stay alive, sure, but you must do so by moving in a way that paints the whole screen. This is satisfying to look at. It forces you to keep moving and to visit all areas, not just stand in one optimal spot.
Inspiration
Inspired by this Croak video.
Notice the rectangular vine thingies that seem to grow thorns after touching them.
Within that game, it looks like you can never visit them again because of that thorny look. That’s also an interesting mechanic.