In the final full version:

 Press [Enter] and type in the cheat code.

 DIEDIEDIE            You all die
 RESIGN               You resign
 REVEAL MAP           Reveals all the map
 PEPPERONI PIZZA      Give yourself 1000 food
 COINAGE              Give yourself 1000 gold
 WOODSTOCK            Give yourself 1000 wood
 QUARRY               Give yourself 1000 stone
 NO FOG               Removed the Fog of War
 HARI KARI            Suicide
 MEDUSA               Villagers become medusa. When villager is killed,
                      he becomes a black rider and if killed again he
                      becomes a heavy catapult.
 PHOTON MAN           Get a 'Nuke Trooper' (Guy with a laser gun)
 GAIA                 Control The Animals (You Loose Control Of Your
                      Humans)
 FLYING DUTCHMAN      Juggernauts turn into the Flying Dutchman
 STEROIDS             Instant build
 HOME RUN             Win the scenario
 KILLX                Where X is the players position (1-8)
 BIGDADDY             Get a cool car with a rocket launcher
 BIGMOMMY             = Bigdaddy, only car is white this time
 BIG BERTHA           Heavy catapults have greater range and damage
 ICBM                 Ballistias get 100 range points
 HOYOHOYO             Priest speed up alot, and get 600 hit points
 JACK BE NIMBLE       Catapults fire peasants who do somersaults as they
                      fly through the air.
 E=MC2 TROOPER        Get a futuristic trooper who fires nuclear missiles
                      which explode when they hit.
 ZEUS                 Troops invincible
 BLACK RIDER          Riding archers turn to Black Knights
 DARK RAIN            Archers mask as trees
 HOYASA        Get a Sumo guy with 800 life points

 In the CGW demo:

 VICTORY              Immediate victory

 In the Net Demo:

 HOME RUN             Wins Scenario.

 In the Beta version:

 STONE                 Gives you 1000 stone
 WOOD                  Gives you 1000 wood
 FOOD                  Gives you 1000 food
 GOLD                  Gives you 1000 gold
 PLAYER[1-8]           Switch perspective to player #[1-8] (be careful
                       not to do this to a defeated player ;)
 RESIGN                Throw in the towel...
 VICTORY               You win
 SUICIDE               RESIGN, except with more fireworks
 KILL[1-8]             Destroys player #[1-8]
 DIEDIEDIE             Kills all other players
 GIVEMEFISSIONMAN      You get the cool guy with the gun
 GIVEMEPHOTONMAN       Like above, except much less powerful gun