During play, press F2 bring up the console. Then type one of the following codes

and press Enter.

invincible 1       God mode 
 invincible 0       Disable God mode 
 health             Full health   
 invisible 1        Invisibility  
 invisible 0        Disable invisibility 
 ammo               Full ammunition   
 fly                Flight mode  
 ghost              No clipping mode   
 walk               Disable flight and no clipping modes   
 stealth            View stealth amount   
 playersonly 1      Freeze enemies   
 playersonly 0      Unfreeze enemies 
 killpawns          No enemies   
 summon <item>      Spawn indicated item      

Item names:

Use one of the following with the summon code:

 echeloningredient.ecamerajammer
 echeloningredient.echemflare
 echeloningredient.edisposablepick
 echeloningredient.ediversioncamera
 echeloningredient.ef2000
 echeloningredient.eflare
 echeloningredient.efraggrenade
 echeloningredient.elasermic
 echeloningredient.elockpick
 echeloningredient.emedkit
 echeloningredient.erappellingobject
 echeloningredient.eringairfoilround
 echeloningredient.esmokegrenade
 echeloningredient.estickycamera 
 echeloningredient.estickyshocker
 echeloningredient.ethermalgoggle
 echeloningredient.ewallmine 
   
 

Thanks to Revolution readers |Stealth|, Speedfight, Andreas Aabrandt, JMN,

Viperomega1 and FateoMcSkippy!