Deathmatch or Co-Op more music
Begin a multiplayer game in Level 23. Complete the level, then reset one of the Jaguars during the ending text. Start a new Deathmatch or Co-Op game on the Jaguar that was reset to play music during the next game in the place of sound effects.
Fire weapons while in automap screen
Hold C + B. If the controls have been reconfigured, hold the buttons assigned to "Use" and "Fire".
Invincibility
Press Pause, * + Pause. Alternatively, press Pause, 9, 4, 7, 4, 9, 2, 1, 0.
All keys, weapons, full ammuni...