Square Enix has four more songs ready for Theatrhythm Final Fantasy. If you imported the Japanese version you can get "Movement in Green" from Final Fantasy X and Final Fantasy V’s first battle theme.
"Ocean Floor Temple" from Final Fantasy
"Battle 1" from Final Fantasy V
"Movement in Green" from Final Fantasy X
"Desperate Fight" from Final Fantasy XII
Each extra tune will be sold for 150 yen ($2) on April 18. Square Enix has the North American version of Theatrhythm Final Fantasy slated for release on July 3rd. Plans for downloadable content have not been announced yet.