The Adventures Of Robby Roto is an arcade game released in 1981.
It's like a cross between Dig Dug and Pac-Man. You are a round red man with a miner's hat named Robby Roto, and you have to go collect your round yellow buddies down under the ground. You can't dig where you want; instead, you have mazes that are visible and invisible to travel through. You must avoid the spiders and monsters that get faster and faster on each level. You get a freeze spell that will give you momentary protection from your enemies. The buddies that you collect follow you around and each level has more of them for you to collect. Eventually you are traveling with a lot of them behind you, making you an easier target to attack. Once you find your buddies, you must find the key to escape.
This game was released as a ROM image that could be played on M.A.M.E. free of charge since it did not do well in the arcades and the rights to the game reverted back to its original creator, thus allowing permission for its noncommercial usage release.