Good, but boring after a long time...
The fun of this game is that people that don't have conditions to have a dog, can finaly have one, even if they can't really touch it... There are lots of things you can do with the dog. From taking it for a walk, from teaching him tricks with your own voice, entering competitions, and many more!!
However, the one thing that bugs me is that if you will always need to take care of the dog, just like a real one... if you keep your game off for a couple of days, the dog will get dirty, and he might even run away. He will come back after a while, maybe with an item.
In short, this game is very interesting, with a great inovation to the Tamagoshi style, however, after some time, you will get bored...