Mighty No. 9 is a side-scrolling action-platformer that channels classic run-and-gun mechanics, following a robotic hero absorbing defeated enemies' powers to grow stronger. Precise platforming and boss battles define its stage-based structure.

Players shoot and dash through enemies, using absorbed abilities to solve challenges and defeat bosses across varied stages. Its retro-inspired design pays clear homage to classic action-platformer conventions. The pacing stays brisk throughout, favoring quick, replayable rounds over a long, drawn-out story arc.