I think out of all the video games I've seen that this one would translate into a movie most easily (its very cinematic). I mean if they could make Mario Bros. into a movie this should be a piece of cake.

What about Orlando Bloom for the prince? (His voice actually reminds me of the voice actor they used for the game.)

Also I think that Parminder Nagra (the main character in Bend It Like Beckham) would be perfect for the Princess.

http://www.imdb.com/name/nm0619406/