I haven't read the mange, nor watched the anime, so I was new to the mythology of Fullmetal alchemist. And, though the story was okay and the acting good, the special effects were a disaster. Kind of ruined the movie, especially if you consider that one of the main characters was a robot, created entirely with computer graphs. So, because of that and the pace of the story, with the few action scenes and the introducing of many characters without a proper background, 3 out of 10.
P.S. there will probably be a sequel, as the story was left unfinished.