All Levels Unlocked:
At the password screen, enter NQRDGTPB to unlock all levels for Vicki or QGQNRTP for Sarge.

More Level Passwords 
2 HJRDCHMC 
3 GGRSGJMC 
4 FSRSMKMC 
5 DQRNBBMC 
6 CSRJGCMC 
7 BQRDMDPC 
8 TJRDQFPC 
9 SGRSCQPC 
10 RJRNLRPC 
11 QGRNRSPC 
12 PSRJCTPC 

Thanks to Revolution reader Agent Orange, Steve, and Thunderstorm!