As MobyGames says:
Clicking on one of the links below will give you information that could possibly spoil or ruin or otherwise make the game less fun. Once you've seen how to cheat, it's hard to forget. Click at your own danger or flee now while you still have the chance.

Super Arcade Modes
Super Weapon Twiddles
Extra Difficulty/Detail Modes
Engage Mode Super Weapon Twiddles
Two Player Mode Super Sidekicks
Command Line Parameters
Jukebox Commands
In Game Codes
Bonus Games
General Tricks