XIAOLIN SHOWDOWN UNLOCKABLES
Alternate costumes
If you want to unlock new costumes, level up the rank from Grass Hopper in Training to Wudai in Training. For certain ranks it will unlock new costumes:
Monk costume
Showdown costume
Robot costume
Street costume
Unlock Chase
After beating Mala Mala Jong in the last level of Adventure mode.
Unlock Jack
By getting at least halfway through the game to fight the Jack Spicer Robot. Defeat it to unlock Jack as a playable character.