Ability-Gated Interlocked Map

World is authored as a single connected space, then seeded with obstacles that specific abilities defeat: a high ledge, a narrow gap, a sealed door. Since the player can go anywhere the current toolkit permits, the map doubles as a quest log, and a remembered obstacle becomes a task. Designers control pacing by controlling access, and backtracking turns into a reward, because old rooms read differently once new powers exist.

Nintendo R&D1 released Metroid in 1986 on a cartridge that had to hold a large world in very little space. Reuse solved that: the same corridors are crossed repeatedly in different states, so the content budget goes into connections rather than new rooms. A non-linear map also suited the game's isolation, since a player free to wander is a player who can get lost, which was precisely the intended feeling.

Structure proved durable because it converts exploration into progression without any external progress bar, and it lets a designer sequence a story using geography. Failure modes are equally durable. Players stall when a gate is unmemorable, maps become chores to re-walk, and ability sets converge on the same double jump and dash. Argument over whether the form needs combat at all is still very much live.