Here are some cheats and tips for the game Asteroids.
Cheat menu:
Enter CHEATONX as a password, then press Select during game play to
display the cheat menu. Press Up or Down to select a level or Left
or Right to select a zone. Press A for invincibility (001 will
appear to confirm correct entry)
Classic Asteroids mini-game:
Enter QRTREATR as a password.
Excalibur ship:
Enter PROJECTX as a password.
Level Password
2 SPACEVAC
3 STARSBRN
4 WORMSIGN
5 INCOMING