As a long time Prince of Persia fan (since Prince of Persia 1), I would say the movie was quite good. The action sequences stay mostly true to the spirit of Prince of Persia. There is no excessive gore (since it is rated PG), but there are some pretty neat stunts and acrobatics. The plot was decently thought out, with a few twists and turns. The general atmosphere of the movie feels exotic but realistic, as if you are in the Arabian Nights with Aladdin, or Ali Baba.
One drawback I found, was that due to the fact that it was a Disney movie, the ending was excessively happy. Eg, Only the bad guys die, all the good guys survive. No consequences. Some people have criticized the fact that the Prince of Persia is white in the land of Persians, but it didn’t seem to make a big difference in the movie. Gyllenhaal plays his role quite well, flashing an endearing mischevious grin at comedic moments.