Hidden Options Menu (NLAND)
Enter password NLAND, then press A + B + C + Down on controller 2 to open this hidden options menu:
Flying Mode (FLYIN)
Enter password FLYIN, then move the orb cursor back to the word Password as seen in the screenshot above. Now, hold A + B + C + Down on controller 2, and A + B + C + Down on controller 1. Note that Down on controller 1 is the last button you should press, otherwise the orb cursor moves off the password selection and cancels the cheat.
If entered successfully, a sound effect plays.
During gameplay, hold B and press A to enable flying mode!
Press A to land.
Enter Action Replay code 014CA2:0113 or Game Genie code CPGA-CCFC to view this unused company logo when entering the options menu.
A couple of minigames are buried in the game code. They aren't accessible without game enhancer cheats, and were probably just simple engine tests used by the developers.
Enter Action Replay code 014CA2:010E or Game Genie code B3GA-CCFC and enter the options menu to play Pong.
Enter Action Replay code 014CA2:010F or Game Genie code B7GA-CCFC and enter the options menu to play a simple vertical shmup.