Cheat mode
Enter "0601" as a password and ignore the invalid password message. Press Start to return to the command center. Then begin a game and hold Select + Up to move up vertically. Press Left or Right to move in that direction, or Select + Down to move down vertically. Hold Select + A to obtain the Noisy Cricket super-gun. If you entered the code correctly, a lightning bolt will appear next to the number of lives remaining.

Level skip
Enter "2409" as a password and begin a new game. Pause the game and press Select to advance to the next level. Pause the game and press A to advance to the next stage within the current level.

View ending sequence
Enter "1943" as a password.

Level passwords
Level Location Password
2 Manhattan 2710
3 Sewers 1807
4 Airport 0309
5 Rooftops 2705
6 Forest 3107