Extra Ark:

Entering Astarte as a name for an extra 2800 Ark.



Sound test:

Enter R1(4), R2(6) at the title screen. The sound of a scream will confirm correct code entry. A "Sound Test" option will now appear on the "Mode Select" screen.



Suezo:

The eyeball monster from Monster Rancher can be found in the game. Although there is no animation, the Suezo is a very powerful trap. To get it, you need to have all four endings saved on one game.