This game isn't any worse than the old ones.
Story: You are a person looking for a dog, so you go to the local kennel and pick out your new best virtual friend! After that there is no real story to it, so I'm not going to rate it upon story.
Difficulty: That actually depends upon the dog that you pick out and it's personality. If it says that it is calm or something like that, it would be like to easy difficulty, but if he is naughty and needed lots of training, it would be the hard difficulty. It's like the teams in Sonic Heroes, only the system works better. 8.5/10
Graphics: The graphics almost look lifelike. The mouth physics on the dog work perfectly, the dog's body animations feel perfect. I also haven't encountered any drops in the game's frame rate. 10/10
Controls: You'll find yourself mostly using the stylus for this game, by throwing things, rubbing your stylus on your dog's head to pet them, and showing them how to do tricks. 10/10
Overall, I don't see why this game got a lower score than the others. It's just as fun. I don't think people should dock it points because it's the same game. The second game that was released wasn't docked any points. Why's that? 9/10. Great Job!