Ruff 'n' Tumble

Ruff Rogers, while playing with his marbles in the park, loses one down a rabbit hole, and follows it down. The rabbit hole turns out to be a teleport to an alien planet.

The planet, ruled by the mad Dr. Destiny, is home to a fearsome army of robots called Tinheads. Ruff finds that his marble collection has been scattered across the planet, and embarks on a quest to reclaim his collection, and free the planet from Destiny and his Tinhead Army.