Level - Code

     Mission 2 - 4JJXB 
     Mission 3 - ZDD1T 
     Mission 4 - RFF1J 
     5 - K4TCG 
     6 - DT1WN 
     7 -QX8J8 
     8 - 
     9 - 
     10 - 
     11- CMODD 
     12 - JGHD3 
     13 - PUUWW 
     14 - WT348 
     15 - 139PO 
     16 - L9IPV 
     17 - 5LIMV 
     18 - YJOJG 
     19 - YFCWJ 
     20 - GDKWT 


To use these codes you must enter gonzo1982 or for the older version 1982gonzo.

Codes - What it does 

     shift v - tracer 
     shift x - teleports 
     ctrl I - invincibility 
     ctrl shift n - finish level 
     ctrl shift x - destroy