ディグダグ
The game has strong parallels to the gameplay in "Dig Dug", released the next year. In both cases, the action takes place in an underground mine, although in "Robby Roto!" the mine is in the form of a maze while "Dig Dug" is freeform, allowing the player to dig in any direction. Some elements are identical; in both games, enemies can begin to travel through the still-filled portions of the map in which case they appear as disembodied eyes. "Robby Roto!" is significantly more complex in gameplay terms, with the motion of the player and enemies being somewhat frenetic and the graphics and sound significantly less developed than in "Dig Dug".