Press 'Enter' and type 'peace' and hit 'Enter' again to be able to activate the codes.
Type in the following and press 'Enter' to enable them

Extra money:
moneyfornothing

Cheaper research:
sciencefornothing
Faster research:
ultrascience

Change research speed:
mybrainisfaster
All research complete:
nobelprize1

Large amount of damage on Screen:
shower
Damage center of screen:
smash
View enemy buildings and units:
hereyouare!
Weaken all enemy buildings in the area:
tromaville
Destroys all enemy units:
byebye

Destroys all enemy units and buildings:
judegmentday
Rearms and heals all selected units:
idkfa

Destroys all of your own Units:
gohome!

Full map:
beautifulworld

Hide current map:
hide
Reveal current area:
moonlight

Set limit for number of units to be commanded in a global-type setting:
limit_up