Slime Planet Eater

You are a translucent slime the size of a small animal, and the planet under you is covered in things bigger than you are. Roll over the grass and swallow it. Then the flowers, then the fence, then the sheep that was ignoring you a minute ago. Every bite makes you heavier, and every kilogram of mass moves the edge of what you can eat a little further out. There is nothing to fail. No timers, no enemies, no currency to manage. A building too large to swallow simply pushes back and bends you around it, until it does not. The pleasure is watching the scale of the world turn over: the tree that filled your screen becomes a snack, the car becomes a crumb, the skyscraper becomes the next goal. Clear one planet and the galaxy map opens the next, each with its own look, its own skyline and its own ladder of things to devour. Hats, trails and skins are yours to collect along the way, purely so your slime looks the way you want while it eats a world.