This movie is a re-imagination of basic Saint Seiya concepts. It uses the Zodiac Temples Arc as a base to its plot. So, I'll consider it as an original work for the most part in this review, as I don't like taking something as a bad thing just because it isn't the same as the old one. The problem is, Saint Seiya: Legend of Sanctuary has a big flaw in its concept: you can't fit this Arc in a single movie, no matter how hard you try.
Lot of concepts are left open because the movie doesn't have time to explain them to you. While it settles a new universe in Saint Seiya franchise, it can't explain itself without relying on fan's knowledge.
Due do the movie format, most of the Gold Saints have no personality at all. With the exception of Aldebaran, Aiolia and Death Mask, they couldn't look more like coadjutors. Milo, who was one of the best re-imagined characters, suffered with little screen time. Aphrodite almost didn't appear at all.
The art was fantastic. The movie's style is a mix of Final Fantasy and Kingdom Hearts, with heavy anime influence, specially in humor scenes. Overall, visually speaking, the battles were very well done. The first appearance of Aiolia created an epic atmosphere. They changed visuals for a lot of characters, Milo even changing gender. I received this all with a positive reaction. Unfortunately, the fights are really short because the movie doesn't have time and the story needs to go on.
The same can be said about the sounds effects. Ambient and movement sounds were very good and matched what we consider an AAA production.
Being honest, I don't think this movie was bad. I enjoyed it. But its pretty clear you can't tell a story like this in one hour and half, and the move suffers from its stupidly fast peace. I would love to see this universe of Saint Seiya in another format like a CG series, even with lower production value. But, in the end, its an 'original' story that can't explain itself and feels too rushed.