The only bright side (besides the fact that I enjoy bad kiddie action/adventure games: it's one of my guilty pleasures) in this game is that it looks pretty good. I could imagine an animated movie looking like this game did. Since this is a Dreamworks game, maybe there was a movie behind it, but if there was, this game doesn't make me want to watch it.....
So, this game is all about using your dragons to fight other dragons in an arena. No flying in this arena. The fighting gets VERY repetitive. When you're not fighting, you're "training," which is fighting against a realtively non-aggressive dragon, so you can get new moves/combos. Since this is supposed to train your dragons, and not you, you need to do the same training again and again with each dragon.
Is there a story? If you call a 30-40 second cut scene where some village kid creates mischief, and then you returning the stolen item so the next tournament can continue a story, well you'll be happy with the story.
Difficulty in the game is a joke, but this is a game made for kids. They might have problems until they get to know the ins and outs of their dragons.
But, I did enjoy playing this game, that is until it was time to get the trophy in the game that requires you to play for 20 hours. That was the hardest one to get, since it meant I had to leave my PS3 on, without me playing it, for about 5 hours. I might have made it in a single save file, but the second playthrough (with the second choosable character) uses a different timer than the first. Since I got most of the trophies with the first playthrough, that file had 15 hours on it, whereas the second had about 4. In that 19 hours, the only things I didn't see were the ending credits that I quit, and cut scenes on the second play (since I also quit them).
I enjoyed the game for a grand total of two hours. The best part of the game is the limited dragon customization. The game is extremely repetitive. I would be impressed if a child was kept interested by this game let alone had the patients to play it. My advice, don't waste your time.