All planets
Select the Historical Campaigns, then at the planet selection screen for Galactic Civil War or Clone Wars, press X, Y, X, Y to unlock all planets for that particular era.

Baby Wars mode
Enter "Jub Jub" as a case-sensitive profile name. All the models in the game will use the Ewok skeleton and turn the game into "Baby Wars". All infantry units will be half their normal size, and their head seems to be much closer to their shoulders. Note: First person view remains the same height.