Borders
If you are playing either SUPER PAC-MAN, GAPLUS, GROBDA, or MAPPY, pause during game play. Now, press the directional button in any direction to reveal 2 special borders where the score count is. If you don't like them, simply press the directional button until you are rid of it. NOTE: This is best experienced with the Simulated Arcade Mode, and will not work on Vertical Mode.
Invulnerable
Make your helicopter invulnerable. At loading screen after given mission orders press and hold L1+L2+R1+R2 for entire load time, CHEAT will appear.
Grobda
At the Grobda screen hold L2+L1+R1+R2 and press START.