In the world of BioMotor Unitron, a meteor brings a new energy source, giving rise to scads of giant robotic creations that eventually become featured attractions in gladiatorial-style arena fights. People come from all over to watch the fights or to try their hand at becoming a top-ranked arena battler. This RPG boasts four dungeons that can shift randomly between two separate layouts. Players can explore them for various items, materials and money. Once enough money is earned, players can upgrade their Unitron for arena fighting. The Unitrons can be almost completely remade from their original configurations and will change visibly with each upgrade. Part creation and upgrading is also possible for over two hundred potential weapon configurations. Strike out into the world, earn a few bags of money, and come away with a fancy fighting machine to explore the rest of the world. Keep winning tournaments to rise in rank until you become the Master of Masters!