Alternate character:
Press one of the following controller combinations at the title screen to play as the corresponding character against Rex.

Character	Code
Bonapart	Press Up, A, C
Edwina	Press Left, B + C, C
Robochic	Press Right, Up, Down
Stump	Press A + C, Right, C
Ramses	Press Right, Left, A
Webra	Press A + C, Up, Right
Guano	Press Up, Right, A + B
McFire	Press Down, C, Right
Skinny	Press Right, Down, Right
Sheba	Press B + C, B, B
Brainiac	Press Right, Right, C
Buff	Press Left, C, B
El Toro	Press B + C, A, Up
Spidra	Press A, Down, B
Weezil	Press Down, Right, Up
Mondu	Press A + B, Down, Left