This game can get repetitive quickly as training dogs does involve repeating the same process.
The length of the game depends on how dedicated you are. Unlocking all the dogs would take About 6 months playing about 30mins every day. Theres also loads of items to get, which would take a lot of walking the dog.
The graphics are really good 3d. It would be nice if you could skip commentary in the tournaments as that is repetitive.