The game has lovely graphics and AI, with lots to do: competitions to enter, walks to take, toys to play with, grooming. Each version has different "starter" dogs, but you can eventually get all the breeds by getting enough "Trainer Points" or by finding items on walks.
This is a sweet game, especially if you love dogs, but it will take the odd bit of learning to do things like teach your dog tricks (you actually have to wait for it to do the action, then tap an icon, then say your "code" for that trick into the mic). You can have up to 8 dogs (3 at home, 5 in a Hotel) so the choice is pretty diverse!
However, be warned. This game does have its downsides.It behaves like a real virtual pet and exists in real time, and while your DS is turned off your dog still gets hungry/thirsty/grubby and the longer you leave it, the worse the dog gets. Eventually it might even run off! (It will come back, but it's a bit like virtual pets in the sense you have to look after it every single day). The game sometimes has a habit of making your dog forget tricks by accident or changing your dog's skills (your dog is brilliant at disc outside the comps but somehow fails miserably in the actual shows, despite loads of practice). Also be aware that the voice recognition system is very sensitive - sometimes commands sound the same and your dog gets confused, for example. You can alter the mic sensitivity or go somewhere quieter if this happens, but it can get annoying if your dog rarely performs the trick you need it to learn.
The game uses all the best parts of the DS - you can blow into a bubble blower to blow bubbles, speak to and call your dog, and stroke your dog by using the stylus. A great, fun game but quite demanding of time and sometimes monotonous (after all, you can only do so much in the game and once you've won all the contests there isn't really much left to do). If you just want a game you can pop open for ten minutes a day on the way to school, work, etc this is a great, fun, easy game to choose. If you want a game with longevity, don't go for this one. I find it terrific fun and very addictive, but it is true that it does turn monotonous and time-consuming after a while.