I'm the mom of 2 girls, 5 and 9 who got this game for Christmas.
To start with, basic reading skills are required. Important information is highlighted, and its possible to get the gist of what to do from the highlighted text, but having a reader helps a lot. Characters prompt you to go to specific areas to achieve various tasks. The storyline and gameplay are almost exactly the same as Petz Catz 2, so owning both is a bit repetitive unless you need to play as both a cat and a dog.
There are multiple layers of gameplay. You can change your dogz clothes, you can buy wardrobes for the town's inhabitants, you can unlock new patterns and colors by catching insects and digging up vegetables or flowers. There are mini games to unlock (which can then be played 2 player) But, mostly you need to follow the storyline, and work to save the magic hat from Ivlet.
As the previous poster mentioned, the slow dialogues get tiresome and there is no way to skip them. However, not too far into the game a magic creature appears who teaches you "how" to save. There are then save blocks (and later warp blocks) which can be used whenever you wish. They don't move, or disappear, or become unusable.
My girls feel that this game is excellent, great for any kid and expect long term enjoyment. However, as an adult, they have both nearly met the main objective in a little over a week of rainy vacation day playing. It's cute, its worth playing. You don't need both Catz and Dogz, and I wouldn't pay $50 for it. Amazon's price was great.