"The greatest melody writer EVER" is perhaps the best short way to describe the Austrian master. His melodies have captured the attention of countless generations of music lovers and composers. Having achieved immortality as a child has set him apart from the rest of "the greatest composers' list".
Freshness is present in all his compositions and even when he tries to be profound and deeply spiritual, Mozart musical purity is always present.
Hollywood has depicted him as a musical clown. Far from the truth. Just like most of what Hollywood does, a degree of mockery is necessary to make the product apt for sale to the masses.
Still, the movie has made justice to the great genius of this magnificent composer by making it clear that he was a GENIUS. 
Turkish march is perhaps one of the 5 most recognizable melodies on the planet. The classical guitar brings out the piece fantastically well.