Press:
 
 F10 + Q = instantly exit the game
 F10 + G = makes you invincible
 F10 + I = all the weapons and goodies
 F10 + W = warp to level 0 thru 18
 F10 + T = tics
 F10 + M = MEMORY USAGE
 F10 + V = GAME VERSION
 F10 + Z = freeze time and monsters