I've never understood why the critics have always hated this film. The animation is gorgeous, and it's held up very well. The cast of voice actors is spot on. The general concept is intriguing, and the story itself is very good!
I've always viewed this story in the same vein as FFVII, but you have the military trying to destroy the planet instead of a corporation, and the scientists have the lead roles in the good guy camp, rather than mages and fighters, even though Dr. Ross has her band of fighters, they just all die.
If you have not seen this, give it a shot. What do critics know anyway?