I waited to write this review until I had beaten the game and got all of the achievements.
I didn't really expect much from this game. I'm not really into these action, kiddy looking, RPGs. I kind of just picked it at random from where it had been collecting dust in my library, but it won my heart. The voice acting is amazing and clever. Arguably, there is a deep philosophical lesson to this game. I won't give it away though. The music? Wow. I have never wanted to buy a game soundtrack, but I do now! At some point in the game, you get a radio, with which you can put whatever song you like on from the soundtrack.
The game has different endings. You beat the game once, and have the option to play the game again with all of your weapons, upgrades, and level intact. This is helpful to get a different ending and/or for achievements.
There is also a attack score mode, where you restart from the beginning, without your upgrades and from level one. In this mode, you can accumulate points and compete on the leaderboards.
There are some really tough achievements, but once you get them you have this huge feeling of accomplishment. They really test your skills as a player.
Buy this game. If you are on the fence, put it on your wishlist, and buy it when it goes on sale. I seriously doubt that you will be disappointed.