Addicting, relaxing and extremely fun. :)
This Sims is exactly like any other Sims game, except for the simple fact that you can own pets this time. :)
You can get dogs and cats (also there is a fish in a little bowl and a hampster/guinea pig i believe, but you dont get that at the pet place, you get those in the regular equipment page) which you can either pick out right at the start of you playing or you can just jump into the game with your player once you create them and buy one at the pet place.
This version allows you to leave the lot that you pick and head to a pet play area where all the pets kind of come and play with each other and also the people go to buy pets and pet supplies. You can also get a collar and clothes to put on your pet in this area.
Although, if you get a pet a way beginning while you are creating your family or people or person, you can customize it to the shape, hair length, color, size, and also pick from many different types of dogs/cats such as dobermans, german shepherds, poodles... etc, almost any kind of dog you can think up. As well as any type of cat you can think up, siamese, main coon, tabby... any kind.
If you do not get one at the start, you have to choose from a select few that are available to you at the pet adoption agency. Also you don't get to choose if it is a male or female, as you would if you created your own pet.
However, if you create your own, and get sick of it you can always get rid of it. Sell it at the pet place, or.. if you get sick of one that you adopted sell that again, and start with a different one.
OR if you will, get a female and male and breed to get a little puppy or kitten.
Again, just like your sims you have to keep your dog/cat happy or they will run away or even die if not fed. Train your bet not to pee in the house, dig in the backyard, or train them to do tricks and be a well mannered pet.
You can bathe your dog, as dogs get messy from rolling around in poo all day, in a tub that you'll have to buy if you're a shower person (or take them to town and bay 50 simoleons to have someone else wash them) get food dishes, beds and an outside hideout if you want, litter boxes are a must for cats.
I'm not going into much more detail given that it's basically just like having a pet. The necessities are the same in the game as in real life, toys and attention.