Halflife: Redemption Cheats (PC)

Load the game with the "hl.exe -dev -toconsole" command line. Then while playing a game,
press ~ to display the console and type "sv_cheats 1" to enable cheat mode. Then, press ~
and enter one of the following codes to activate the corresponding cheat function:   
RESULT - CHEAT CODE -   God mode - /god   All weapons with full ammo - /impulse 101   No
clipping mode - /noclip   Opponents ignore character - /notarget   Third person view -
/thirdperson   Adjust gravity - sv_gravity [-999 - 999999]   Obtain item - /give [item
name]   Map select - /map [map name]

Start the game with the command
line parameter hl.exe -dev -toconsole .
Now while playing you can press ~ to
bring up the console. 
It is also reported you can go to
the console by pressing ~ then type in sv_cheats
1 instead of having to do the command line
parameter above

Enable cheat mode, then activate the "/map redE3M5" code to advance to episode 3, mission
5. Locate the door that does not have a handle in that level. Enter the "/noclip" code
and walk through the door to find another door covered with smiley faces.