Postby Raymunator » Wed Sep 21, 2022 9:42 am
Most Mario games, official or not, have about 40 to 60 levels, and that number has increased with time. I think Mario 3D World has like 100 stages.
However, how many levels you should make ultimately boils down to personal choice and your personal design philosophy. You could make like 20 levels but make them very long of full of all kinds of secrets, or make it like Mario 3 where you have a ton of levels that are not terribly long but are still pretty solid design wise.