In process of setting up new runs. Is there a simple way to replay a certain section of a run, if the game itself has no save.

Example: Super Mario Land on the Gameboy, it contains 32 levels, subdivided into 8 worlds. Is there a way to start a run at world 4? To "practice" world 4. Games like this have no save, once you've passed world 4, it's passed. Only way to go back to world 4, is to start over at world 1.

Super Mario Land on the Gameboy is one example, but applies to all games like it that don't allow the save.

if you are playing on emulator you can just make practice save states? or you can play on a completed file in some games

Hmm, ok, will look into that. It is specifically for games with no save

For Super Mario Land in particular, beating the game once unlocks hard mode, then beating that unlocks a level select.