Dig tunnels, then pump enemies until they pop (keep pumping or they deflate). Undermine rocks to crush enemies — several at once is worth big bonuses. Ghost eyes drift through dirt. Dragon-types breathe fire sideways. After two rocks fall a bonus item appears in the middle. The last enemy flees to the surface!
Desktop: arrows/WASD move · Space pump (hold or tap) · P pause · M mute · F full screen.
Phone (portrait): d-pad bottom-left · PUMP bottom-right · ⚙ change game.
Controller / Xbox: stick move (push lightly to creep, fully to run) or d-pad · A pump · B or Start pause · Y change game · View mute · Start begins a game.