Metroid: Other M, the latest game in the Metroid series, was heavily criticized for the contradictory portrayal of its avatar protagonist, Samus Aran. This article analyzes these critiques within the 25-year history of the Metroid series, noting intersections with literary theory, cognitive science, geography, and cinema. "Mapping Metroid" argues that player dissatisfaction is a result of Other M’s inconsistency in balancing gameplay constraints with player agency, and the game’s failure at "imperative" storytelling. The maps in Other M and its predecessors are treated in depth, since the relationship between cartographic and gameworld spaces must be "read" dynamically by players to progress; these maps reflect the affordances of each game, and how those affordances contribute to player enjoyment or frustration. The article concludes with the suggestion that paying attention to signifying spaces may help design better games and help situate video games within a wider discussion of theories of postmodern subjectivity.