Super Mario World

Nintendo launched the SNES together with this cartridge, and its main change is structural: instead of a chain of levels there is a map. Some stages have two exits, a regular one and a hidden one, and the second opens a separate branch on the map. A completed level is therefore never closed off for good; you go back to it for the second exit. The switch palaces act retroactively: a pressed switch fills in the dotted outlines of blocks in all the levels at once, including those already completed.

Yoshi works as expendable transport. He swallows enemies, the color of the shell in his mouth changes his abilities, and a hit taken while riding costs you Yoshi himself: he runs off and can be caught again. The cape adds flight from a running start, and anyone who has mastered the rhythm of rising and dipping passes over a level above everything built in it. The designers didn't forbid this, because the substance of the game was moved from the individual level to the map as a whole. The battery in the cartridge stores your progress, and the world becomes an object that you take apart piece by piece in your own order.