Zoradius mini-game:
Go to Boss Battle mode in Extra Missions and fight Vic Viper. When fighting Leo, pause the game and press Up, Up, Down, Down, Left, Right, Left, Right, L1, R1. The Zoradius mini-game is now found at the Extra Missions screen.

All power-ups for Zoradius:
During Zoradius, pause the game and press Up, Up, Down, Down, Left, Right, Left, Right, L1, R1.

More Jehutys and Versus Mode:
Beat the game to unlock more versions of Jehuty as well as Versus Mode.

Different ending:
Beat the game with an "A", "S", or "SS" rank to get new pictures after the credits.

Auman Anubis frame:
Beat the game and save it. Now load that saved game file. On the level where you have to open two locks to open a gate, go to the left path and then go left to the Metatron. You'll see a pile of rocks. Use the Vector Cannon and blow up the rocks. Then enter the tunnel and you'll fight Araum Annubus. Beat him to get his frame for Versus mode.

Thanks to Revolution readers Ryan Gibb and Andy McDowell!