God mode:
Press Start to pause game play, then hold L + R and press A(2), B, A(5).

Disable God mode:
Press Start to pause game play, then hold L + R and press A(2), B, A, B(4).

Computer map:
Press Start to pause game play, then hold L + R and press B, A(7)

Radiation suit:
Press Start to pause game play, then hold L + R and press B(2), A(6)

Invincibility:
Press Start to pause game play, then hold L + R and press B(3), A(5)

Berserk:
Press Start to pause game play, then hold L + R and press B, A, B, A(5)

All weapons, items, keys:
Press Start to pause game play, then hold L + R and press A, B(2), A(5).