I will be buying this game's soundtrack.
I really enjoyed it until about the midway mark (about 20 hrs in for me), then it started to drag. Because I did the first half without a walkthrough, hunting around for every treasure, I ended up a bit overpowered due to the relatively high encounter rate in several places, so none of the bosses were difficult at all -- Lucifer being the only tough one thanks to having an attack that could wipe out my fully healed party with one shot (on my second try, it got the first attack in the battle and used that attack, so that attempt ended quickly). The Guardians ended up doing so much damage very shortly into the game that I didn't even need to use what the game is named after -- the ARMs.
Since there are only about a half dozen different sound effects for when the enemies get hit (they sound to me like a cat, dog, chicken, a dull thud, and maybe one or two others), quite a few of them became humorous to me since the associated sound effect is nothing like what I would imagine it to be. And speaking of the sounds, I'm giving the game the benefit of the doubt and attributing this to playing it on a PS3, a few times it stopped playing some of the sound effects making the battles have no sfx. This wouldn't have been so bad except that the little beep when you use Radar also stopped playing rendering that Tool useless if the visual clue wasn't on-screen. If this is an actual game glitch, and not due to the PS3 emulation, I knock my score down to a 7/10.