Unlimited Ammo:
From the drop down console (~) put in iamtheone to enable cheats and type allammo to summon that item

God Mode:
From the drop down console (~) put in iamtheone to enable cheats and type god to get god mode

Summon Item Mode:
From the drop down console (~) put in iamtheone to enable cheats and type summon <item> to summon that item. Also reported as summon unreali.<item> (With no spaces between . and item)

Items list:
cannon
eightball
flakcannon
nali
skaarjwarrior
quad shot
WarHeadLauncher
Enforcer
DoubleEnforcer
Minigun2
PulseGun
ShockRifle
SniperRifle
UT_BioRifle
UT_Eightball
UT_FlackCannon
Chainsaw

Opponents:
warlord
titan
stone titan
squid
slith
skaarj
skaarjwarrior
skaarjscout
skaarjlord
skaarjberserker
skaarjassassin
iceskaarj
skaarjtrooper
skaarjsniper
skaarjofficer
skaarjinfantry
skaarjgunner
queen
pupae
nali
nalipriest
mercenary
mercenaryelite
manta
giantmanta
cavemanta
krall
lesserkrall
krallelite
gasbag
giantgasbag
fly
devilfish
cow
babycow
tentacle
brute
lesserbrute
behemoth
bots
skaarjplayerbot
humanbot
malebot
maletwobot
malethreebot
maleonebot
femalebot
femaletwobot
femaleonebot
nalirabit
horsefly
blobelt
biterfish
bird1
parentblob
horseflyswarm
deadbodyswarm
biterfishschool

Weapons:
From the drop down console (~) put in iamtheone to enable cheats and type loaded to get all weapons

Fly Mode:
From the drop down console (~) put in iamtheone to enable cheats and type fly

Disable Flight and No Clipping Modes:
From the drop down console (~) put in iamtheone to enable cheats and type walk

No Clipping:
From the drop down console (~) put in iamtheone to enable cheats and type ghost

Game Speed:
From the drop down console (~) put in iamtheone to enable cheats and type slomo # (Where # is a number from 1.0 to 10.0)

Add Bots:
From the drop down console (~) put in iamtheone to enable cheats and type addbots # (Where # is the # of bots to add)

Eliminate Enemies of a type:
From the drop down console (~) put in iamtheone to enable cheats and type killall <enemy type> (Use enemy names like nali, skaargwarrior, mercenary)

Examples for Killall and Summon codes:
warlord
titan
stone titan
squid
slith
skaarj
skaarjwarrior
skaarjscout
skaarjlord
skaarjberserker
skaarjassassin
iceskaarj
skaarjtrooper
skaarjsniper
skaarjofficer
skaarjinfantry
skaarjgunner
queen
pupae
nali
nalipriest
mercenary
mercenaryelite
manta
giantmanta
cavemanta
krall
lesserkrall
krallelite
gasbag
giantgasbag
fly
devilfish
cow
babycow
tentacle
brute
lesserbrute
behemoth
bots
skaarjplayerbot
humanbot
malebot
maletwobot
malethreebot
maleonebot
femalebot
femaletwobot
femaleonebot
nalirabit
horsefly
blobelt
biterfish
bird1
parentblob
horseflyswarm
deadbodyswarm
biterfishschool

Go to Map:
From the drop down console (~) put in iamtheone to enable cheats and type open <map>

3rd and 1st Person Views:
From the drop down console (~) put in iamtheone to enable cheats and type behindview1 or behindview0

Time Stopped:
From the drop down console (~) put in iamtheone to enable cheats and type playersonly