Mr. Do! is an interesting maze game variant, that
adds several twists to the Pac-Man formula: 'digging'
your own maze (ala Dig Dug), Collecting the letters
E-X-T-R-A to get extra lives (verses awarding them at
set score milestones), and multiple ways of clearing a
level (collecting all fruit, killing the enemies, finishing
out EXTRA, or if you're lucky, finding a diamond.) This
variety really adds to the replay value.