Tales of the Tempest is the type of game you need to go into not expecting Tales of the Abyss.
Personally, I don't understand the logic behind that at all. A full run through Tales of the Tempest left me with that "just played a great game" feeling. As a Tales vetran, I've played all the games and had no reason to be disappointed with this one.
Tempest has a few differences Tales fans might not be happy with, namely the confusing menu and inability to use shortcuts in battle or command your party members to take certain actions. This game is also quite significantly shorter than any other Tales game -- most people are finished with it in 10 or so hours.
Graphics-wise, it's a decent looking game. Voice acting is very limited, in fact none of the characters' normal dialogue is voiced, though there is voice work as usual for battles and a little when you attempt cooking. The cooking system in Tempest is a change from the Tales norm -- instead of just gather ingredients and cooking right away, you play an easy cooking mini-game using the touch screen and stylus.
The game's battle system is very easy and quite fun; even bosses usually don't present much of a challenge (which results in you being surprised by how hard the final boss is). Its easiness can compensate for not being able to use shortcuts and order a cure spell right away when you're in a pinch.
The characters were my main source of enjoyment. Were the game longer, I would've liked to see more character development because most of them had the potential for greatness. Their interactions were amusing, and I believe, had the story been voiced, they would've become much more colourful and likeable.
Overall, understanding Tempest's story made it that much better -- it was a good story. Nothing earth-shaking, but good all the same.
This game is far too underappreciated; it isn't close to recieving the credit it deserves and definitely is not as bad as people say it is.