Cheat mode:
Press ' during game play in single player mode to display the chat window. Enter one of the following codes in single player chat to activate the corresponding cheat function.

Effect - Code
2D players - turnpunchkick
Large torsos when breathing - 1-900
Very big heads - meganoggin
Big heads on all characters - bignoggin
Full ammo, refill items - 5fingerdiscount
Toggle victory conditions - explore
Disable AI - nobrainer
Stumpy characters - stumpy
God mode for selected person - avatargod
God mode for team - teamgod
Flatulent walking - silentbutdeadly or fastactionresponseteam
Large feet and hands - clodhopper
Invisibility for team - teamshadow
Invisibility for player - theshadowknows
Activate debug keys1 - debugkeys

1. Once this code is active, the features in the "Debug commands" section below may be used.

Debug commands:
Enable the "Activate debug keys" code and press [F10] to enter debug mode. Press one of the following keys to activate the corresponding debug function.

Effect - Key
Screenshot - [F2]
Enemy view - [F6]
Suicide - [F7] or [F8]
Return to normal view - [F9]
Exit debug mode - [F10]
Level skip - [F12]
Adjust lighting - [ or }
Toggle AI - A
Third person views - V or B
Adjust elevation - [Comma], [Period], or /