All the available cheats in Age of Empires III are listed here. To enter a cheat codes, press "Enter", while in a game to activate the chat box. Then type the following cheat codes to gain the effect listed immediately after the code is entered.
The "sooo good" cheat is a reference to the Homestar Runner sub-series "Teen Girl Squad", in which a similar "[noun]'d" occurs whenever one of the girls is killed. In addition, "Sooo good!" is the girls' catchphrase.