The file contents four basic maps. In order to play on those you have to copy them into your aoe3demo/rm folder. Unfortunately the demo requires to rename them to either texas.xs or new england.xs (save the original texas and new england map first ;)
Those maps are just basic stuff , nothing to special. I made them to get a feeling on how those common maps will play in aoe3.
They are only for 1v1 and not tested that much so there might be some glitches left.