Press the (SHIFT) and the [@] key or the [~] key (on some systems) to make the console window appear. Then type any of the following codes:

full ammo and full life - WhyDoIPlay
gives you 100% health - InjectLife
Cop Uniform - iamthelaw
Leaves you with 1 Health - iamsolame
flying modes - likeabirdy
Gimp Suit - smackdatass
lots of cash - jewsforjesus
leave you with 1 health - alamode
lots of dog treats - boyandhisdog
retuen to regular walking mode - walk
cats bounce off walls - OFF - splodincats
cats bounce off walls - ON - boppincats
shoot cats from guns - OFF - dockincats
shoot cats from guns - ON - rockincats
body armor - blockmyass
lots of health pipes - headshop
lots of catnip - iamtheone
rocket cam - fireinyourhole
lots of spinning cats - catfancy
Hit Enemy in head with hammer for silly slo-mo - limbsnapper
Throw Lots of Hammers - hulksmash
enables 1 shot kills when shot in head - headshots
All Weapons - gunrack
Full Ammo - blastacap
Throw Lots of Scythes - reaperoflove
Throw Lots of Machettes - bladey
Fly mode - Fly

Type "Sissy" in the console window while in-game then:enter "set P2Player bGodMode True" to make you invincible or "set P2Player bGodMode True" to make you mortal.These codes must be entered while you are playing in maps.