In the game hit Shift+; and then type the following codes:

psi_full - fully restores psi points
ubermensch - pumps up all your stats and skills
add_pool - gives additional build pool points
summon_obj x - where x is the item you want (see below)

WEAPONS
psi amp
wrench
pistol
shotgun
assault rifle
laser pistol
EMP rifle
electro shock
gren launcher
stasis field generator
fusion cannon
worm launcher
crystal shard
viral prolif

AMMO
standard clip
HE clip
AP clip
timed grenade
EMP grenade
incend. grenade
prox. grenade
toxin grenade small
prism
large prism
pellet shot box
rifled slug box

PATCHES
med patch
medical kit
detox patch
rad patch
psi patch
psi booster
speed boost
strenght boost
int boost

ARMOR
light armor
medium armor
heavy armor
reflec armor
vacc suit
worm skin

ITEMS
soda can
chips
implants
wide machinery
brawnboost
endurboost
swiftboost
smartboost
wormblood
wormheart

MONSTERS
blast turrent
laser turrent
turrent slug thrower
protocol droid
midwife
rumbler
delaxroix
grub
swarm
overlord
greater over
arachinightmare
male appar.
female appar.
crewwoman
invisible arachnid
turret rocket
crewwoman
malecrew

CARDS
med card
science card
crew card
r and d card
rec crew key
med annex key
cryo card
crew 2 card

RESEARCH ITEMS
monkey_brain
rumbler organ
grub organ
swarm organ
mn. over. organ
gr. over. organ
arach. organ
midwife organ

OTHER
molec. analyzer
ICE pick recycle
r 1 nanite
5 nanites
10 nanites
20 nanites
fusion shot
EMP shot
explode barrel
rad barrel
stats trainer
tech trainer
weapon trainer
PSI trainer
wormgoo

CHEMICALS
Type summon_obj chem #
1 fm fermium
2 v vanadium
3 ga gallium
4 sb antimony
5 y yttrium
6 cu copper
7 cf californium
8 na sodium
9 os osmium
10 ir iridium
11 as arsenic
12 cs cesium
13 hs hassium
14 te tellurium
15 mo molybendium
16 tc technetium
17 ra radium
18 ba barium
19 se selenium