Type in the Main Screen LEVELX (with a space behind the X)
Now you can use the following key combos during gameplay:
<Alt>-<0> : More Speed
<Alt>-<1> : All Ammo
<Alt>-<2> : Weapons Upgrade
<Alt>-<3> : More Energy
<Alt>-<4> : God Mode
<Alt>-<6> : Ends the current mission
<Alt>-<7> : Deactivates enemies
<Alt>-<8> : Heli Mode
<Alt>-<9> : Tank Mode
Start a Network Game. Use HAMMER as your name to get an unique series of
pre-recorded messages.