Space Ace/Dexter (voiced by Sparky Marcus as Dexter and by Jim Piper as Space Ace) and his sister Kimberly (voiced by Nancy Cartwright) work for Space Marshall Vaugh (voiced by Peter Renaday) to keep the peace in the universe. They fight the evil alien commander Borf (voiced by Arthur Burghardt) and keep him from invading Earth. Again, as with Donkey Kong, Ruby Spears took artistic license with the relationship with Kimberly and Dexter. In the Don Bluth film canon, Kimberly is Ace's girlfriend, not sister. Also, in the video game, Dexter had certain chances to revert to Ace, his full-grown self, whereas in the cartoon the Ace/Dexter phases seemed to happen on their own and at often incovenient times for the hero.