I didn't totally finish it, but here are my thoughts.
I agree with Dorelian, it was annoying that you could see the map bounds in the water, both during cinematics and normal gameplay.
As for the music, I never play wc3 with sound turned on, so I can't comment on this.
The cinematics were generally nice, but there were some problems. My units were being attacked and killed so I lost during a cinematic.
I think that it would be a good idea to use black fade filters when a new cinematic ends/starts, because it looks a bit weird to me when the camera and the units just suddenly move.
It was pretty nice to see the units speaking, but it was a bit annoying that during a dramatic cinematic, one of my soldiers were asking for beer.
I preferred the RPG part of it way more than the TD and hero defence parts, it might have been because I found them too long, and generally don't like them extremely much.
The terrain was nice, and the plot was fine too. Most of the map was really good, in my opinion.
The only big problem that I found was units being killed during cinematics - seriously, this must not happen. Better pause all units that has nothing to do with the cinematic and make them invulnerable, or do something else. Just be sure that this is fixed.
It will get my approval when you fix that bug.