Unlock Titanium Ranger
Complete the entire game, making sure to save the Titanium Ranger (at the end). After the Credits, you'll have to save and then restart your game. The Titanium Ranger is now selectable.
Level Skip
From the Main Menu, select the "Codes" option and then choose "Enter Code". Enter OMEGA and you should see the message "New Code Activated". Now select the Activate Codes option and press Left or Right to switch levels.
Cheat Codes
From the Main Menu, select the "Codes" option and then choose "Enter Code". Now enter any of the following codes:
Granted Wish - Cheat Code
Infinite continues - FOREVER
Infinite lives - IMMORTAL
Infinite health - D4B7E1O9G7
Infinite RPE moves - N7F6U2A5A1
All galleries - SHOWCASE