Level select:
Enter ZZZCYX as a password.

Invincibility:
Enter XBABYX as a password. The word "Correct" will confirm correct password entry. You will lose energy, but no lives, during game play.

Rapid fire:
Enter YAYAYA as a password.

Bonus mission:
Move south after completing the objectives in mission 1, phase 2. Enter the alternate exit in the dead end canyon to start a bonus underwater mission.

Level-Phase	Password
2-2	CBYXYC
3-1	XABXAB
3-2	AZCBXC
4-1	YYBBCY
4-2	BAXCXX