Sound test:
Press L or R at the Lucas Arts logo.

Bonus level:
Enter BCDF or GYLM as a password.

View end credits: br> Enter XWJR as a password.

Cheerleaders vs. The Monsters bonus level:
Enter WBGR as a password to begin game play on level 9 with all ten victims. Rescue all victims on each stage up until level 12 (Mars Needs Cheerleaders) to reach the "Cheerleaders vs. The Monsters" bonus level.

Level	Password
2	PHZB
4	XHRS
5	FHRX
6	PHRP
8	WBGR
9	NBGW
12	GFCY
13	FRCR
16	KKYM
17	RKYL
19	DBJK
20	BXBS
21	PXBG
24	GYLM
25	XYLZ
28	GLZJ
29	XLZG
32	XJQY
33	WJQK
36	KZVJ
37	BZVG
40	KRPY
41	BRPK
45	BLHR