Maybe you are talking about Ultima Online, because the original Ultima games predate Time Bandits. Also, Marvel multiverse would have been mostly influenced by DC Comics alternate Earths, with Earth-2 introduced in 1961.
Richard G was HEAVY into time bandits (1981) and Ultima 2 (1982) on were heavily influenced and easter eggs for the movie are spread all over. The airplane in New San Antonio for example...