Unlock Zulu and Xtal, then accumulate twelve more hours of game play.
Fight as Zulu and Xtal
Successfully complete the game under the normal or higher difficulty level.
Fight in Neco's stage
Unlock Neco, then hold L + R while selecting Xtal's stage at the stage selection screen.
Neco Hammer mini-game
Enter the "Key Config" option and change all the buttons to "No Use". Use the "Test 2" option that appears to play a mini-game that involves hitting Neco's head with a hammer.
Phalanx mini-game
Unlock the Neco Hammer mini-game, then accumulate three more hours of game play. An option to play Mini-Phalanx will appear after that time.
Time attack mode
Successfully complete the game under the normal or higher difficulty level.