Start the game with the command-line parameters:
-dev -console -game rewolf
(example: c:\gunman\gunman.exe -dev -console -game
rewolf)
...then use any of the codes listed after pressing ` to bring down
the console:

Code - Result
/god - God Mode
/noclip - No Clipping Mode
/map X Goto Map X
/impulse 101 - All Weapons and Ammo
/give X Give Item X
/notarget - Invisibility

Item Names:
weapon_fists;
weapon_gausspistol;
weapon_shotgun;
weapon_Minigun;
weapon_beamgun;
weapon_dml;
weapon_Spchemicalgun;
ammo_gaussclip;
ammo_buckshot;
ammo_minigunClip;
ammo_beamgunclip;
ammo_dmlclip;
ammo_chemical;
item_healthkit;
item_armor;
player_armor;
vehicle_tank.

Map Names:
takeoff;
rusted;
meltdown;
highnoon;
frontier;
cinematic1;
cinematic2;
cinematic3;
cinematic4;
city1a;
city1b;
city2a;
city2b;
city3a;
city3b;
end1;
end2;
mayan0a;
mayan0b;
mayan1;
mayan3a;
mayan4;
mayan6;
mayan8;
rebar0a;
rebar0b;
rebar2a;
rebar2b;
rebar2c;
rebar2d;
rebar2e;
rebar2f;
rebar2g;
rebar2h;
rebar2i;
rebar2j;
rebar2k;
rebar2l;
rebar3b;
rebar3d;
rebar3e;
rust1;
rust2a;
rust2b;
rust3a;
rust4a;
rust4b;
rust4c;
rust5a;
rust6a;
rust6b;
rust6c;
rust6d;
rust7a;
rust7b;
rust7c;
rust7d;
rust7e;
rust8a;
rust9a;
west1;
west2;
west3a;
west3b;
west4a;
west4b;
west5b;
west6a;
west6b;
west6c;
west6d;
west6e.