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.

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.

Time attack mode
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.

Fight as Neco
Unlock Zulu and Xtal, then accumulate twelve more hours of game play