The Animation Review
Here, I give my own opinions on the Animation. I won't say that you'll agree with me, but you're not the one who's running this website.
Story and Plot
The story of Phantasia is condensed, of course, but new sequences have also been added and existing scenes edited for the Animation. Plus, the "past" portion of the story us cut down from the original 2/3 of the story to being only half, as Cress and the gang return to the present at the end of the second episode. This was helped as well since they moved the Heimdall events to the future, rather than keeping them in the past.
While the pacing is fast, it's still easy to follow along. I watched the Animation before I played the game and was able to follow along pretty well, and got to pick up even more after playing the game. So it's able to stand on it's own in addition to acting supplemental to the game.
Animation
The animation is superb; Production I.G. has done a wonderful job of animating Kosuke Fujishima's original designs. The backgrounds are also beautiful and intricate, and serve the product very well. Every single frame is beautifully done, as can be expected with how long they took to work on the anime. I can find absolutely no flaw with it; the movements are fluid, the characters come to life, and the spells' CG are done wonderfully.
Sound and Music
The opening and ending themes don't really stick out to me, personally. On another note, though, the opening theme's title, "The End of a Dream", surprises me, considering that the games' opening theme was "The Dream Will Not End". The opening theme is a bit more catchy than the ending, but not by much, in my opinion.
The anime's music was done by someone other than Motoi Sakuraba, which did well, in my opinion; it stood out a bit more than the game's music.
The voices were very well done in both Japanese and English; veteran voice actor Johnny Yong Bosch does Cress' voice (funnily enough, this isn't his first time acting in a Tales role; he voiced Guy Cecil in Tales of the Abyss). The only voice I would have to comment negatively on would be Mia Bradley, who performed as Mint Adenade; as Mint's character archetype is typically hard to find a completely natural voice actor for, Mia did a good job, but at some points it still fell flat.
Overall
Tales of Phantasia the Animation is all on a single DVD disc, so it's a great investment. Everything in this DVD is top quality, and is excellent whether you'd played the game or not.