Submitted by: conner54
Load game with the command line: hl.exe -dev -toconsole.
Then, press ~ if the orange text on the screen does not disappear.
During gameplay, press ~ to display the text prompt and type in sv_cheats 1.
Press ~ and enter one of the following console commands.
Note: You can only use cheats when the maximum players is set to “2”.
Toggle God mode - godmode
All weapons - giveall
Toggle no clipping mode - cl_noclip
Toggle opponents ignore character - cl_notarget