Enable bosses:
At the title screen, press Up, Triangle, Down, X ,
Left, L1, Right, R1. You'll hear a sound to confirm. This will open up 5 more
playable characters in the new "Ultimate Battle 27" mode.
Thanks to Revolution readers Anak Agung Gde Mahendra, super sai-jin Goku, Timothy Chen, and Humphrey Ongkosandjojo!