An anonymous reader writes with this excerpt from Significant Bits about how the early level design in Super Mario Bros. 3 gradually introduced players to the game without needing something as blatant and obtrusive as a tutorial:
"Super Mario Bros. 3 contains many obvious design lessons that are also present in other games, e.g., the gradual layering of complexity that allows players to master a specific mechanic. What surprised me during my playthrough, though, was how some of these lessons were completely optional. The game doesn't have any forced hand-holding, and it isn't afraid of the player simply exploring it at his own pace (even if it means circumventing chunks of the experience)."