Level Codes

Stage1 - NORMAL, XHGDR : HARD, PLKUM : VERY HARD, PVTSL 

Stage2 - NORMAL, WKUC4 : HARD, JE5SH : VERY HARD, SKDJF 

Stage3 - NORMAL, YSM51 : HARD, DFY3B : VERY HARD, 3DYNG 

Stage4 - NORMAL, B7D8F : HARD, K9D3H : VERY HARD, 9BG3S 

Stage5 - NORMAL, 3GHSL : HARD, NMWQ9 : VERY HARD, KJWJK 

Stage6 - NORMAL, AZLM1 : HARD, 16G3L : VERY HARD, E2J7H 

Stage7 - NORMAL, JAHSG : HARD, WL3CZ : VERY HARD, ZX78Y 

Stage8 - NORMAL, UN63A : HARD, LPQ6T : VERY HARD, TRIB4 

Stage9 - NORMAL, VAZ2P : HARD, SRCM8 : VERY HARD, TRD78 

Stage10 - NORMAL, 9TT5W : HARD, PAEN8 : VERY HARD, 1LPQD 

Various Cheats
     Enter  your  name  or  type  during gameplay, 'GONZOANDJON'. Then
press any of the following:

Shift + X = Teleport 
Ctrl + V = Invisibility 
Ctrl + - = Show Framerate 
Ctrl + Shift + N = Win Mission 
Ctrl + Shift + X = Kill All Enemies
Ctrl + I = Invincibility