If you're a mature gamer and can appreciate a sophisticated yet enjoyable story, then this game is for you.
Story
The story reminded me a lot of Suikoden 3 in that you will be observing a set of events from the perspective of multiple characters. Some people may be put off by this kind of story telling, but I personally found it very cool and helpful considering how hard the story would be to follow without this feauture.
The setting for the game, which consists of Valkyries, fairies, and dragons, was also pretty fresh for me. I was not very well acquainted to the rich mythology that is behind this game, so it was a pleasure learning about it all as I experienced the game events first hand.
The characters in this game are also VERY good. Sure some characters are definitely more one-dimensional than others, but most of the cast are fairly well-developed and for some reason, extremely likeable. Let me just say that you will change your "favorite character" more than once throughout the game.
Gameplay
The gameplay is very good, but it's still Odin Sphere's weakest link. First of all, the learning curve is a bit heavy for this game and the first character you play as is rather difficult to control. So my advice is to keep the game on EASY (I know I know, just swallow your pride and do it) and slowly learn how the gameplay mechanics are supposed to work. Once you get how to plant seeds, upgrade your psypher/health, and mix material with ingredients, you'll be in pretty good shape to bump the difficulty back to normal.
Sadly, after you've mastered the game mechanics and have become very adept at taking advantage of the system, the game becomes a bit repetitive. Yes, all five characters play differently for the most part and the action is pretty satisfying, but you'll be growning the same seeds, making the same decisions, and plowing through the same environments. The great story does remedy this quite a bit, but it is a definite weakness for the game.
Graphics
The game actually gives you a pretty bad first impression in terms of graphics but as the game progresses, you'll learn why so many people praise this part of game so highly. Though the initial battlefield background is banal and empty, some of the other levels host backgrounds that seem to belong in a art gallery. The character animations are also lovely to say the least. I LOVED the chick/chicken animations btw.
However, there are some performance problems with the game especially when you attack a lot of enemies on screen. This is especially an issue in one particular environment, which i found very unfortunate since it is one of the more interesting locales. Other than that though, the overall graphics and the amount of DETAIL they put into this game truly make it seem like a real world.
Sound
The music too grows on you over time. At first, I thought the tunes were a bit too epic or too playful, but after visiting the environments numerous times, I have to say the music fits almost perfectly to their respective locales.
The voice acting too is very well done and really makes the characters more likeable. You also have the choice of playing the game with Japanese voices in the game, so if you're an anime junkie like me, you'll like the kind of voice acting presented in this game. However, the English voice cast also does a splendid job and definitely keeps up with Atlus's tradition of finding great voice talents for their games.
Value
This is a LONG game. It took me about 25 hours to beat this game and i admit i switched the difficulty to easy around the middle so I could get through the game a lot quicker (I have a fairly busy summer). Overall, it was time well spent with the game and I am very glad to have played it.
Conclusion
After becoming tired of half-cooked single player modes of current gen titles, I have to say Odin Sphere was a breath of fresh air. Though its not perfect by any means, the story it tells and the characters that drive it definitely make it a worthwhile experience. And considering how affordable this game is now ($10-$20), it's a steal for anyone who wants to dive into a rich new game world they can fall in love with,