To play as the Minotaur WITHOUT CODES, collect 50 coins in the Mountain 
Cliff bonus round before time runs out. The portal to the bonus round is 
accessed by standing in front of the door (with skull and crossbones) 
that is near the end of the Mountain Cliff level. The door is near a 
ramp on the edge of a cliff and will transport players to a classic 
Gauntlet bonus round. 

Alternately, to play as Minotaur WITH CODES, raise Warrior to level 10. 
Then, at the character selection screen, hold Turbo and choose the same 
character. Warrior will turn into Minotaur!