Problem with Another world is that people who know what the hell it is will also know the entire plot of the movie.
And I believe there are actually a PacMan the movie in the works as well.
How about Lode runner then? Or for the ones here who like a bloody movie, how about Blood and Blood 2?
The Ultima series would indeed make great movies as they have a good long plot to start with, or at least plot which takes a bit of time to complete. Just stick to one of the plots instead of trying to make one yourself like they did with Final Fantasy. And use actors damn you.