Full pause screen
Pause the game and press X and Y at the same time.
Unlock Pride
Complete the game with all 7 original characters to unlock Pride.
Unlock Mel
Once Pride is unlocked, you can unlock Mel. You must complete the game with all 8 characters (7 original plus Pride).
Open Extra Arenas
Complete the game with 9 characters. That includes the 7 original plus Pride and Mel. This will unlock three arenas. These arenas do NOT show up in the arena selection menu. Instead, access the arenas by going to the arena selection screen and pressing either left or right until the selection cursor goes off of the screen. A new box will pop up with the words "Extra Arena".
Open The Extra Options In The Option Menu
Each time you complete the game in Basic Mode using a different character, a new option is unlocked in the options menu.
100,000 credits for shop mode
If you ever pick up item #103 (a red turban), you can sell it for 100,000 credits in shop mode. There's no way to "force" item 103 to show up, so it's basically random.
