Unlike in Sims 2: Pets and The Sims: Unleashed, the player can directly create and control pets. Also, adds a new town called Appaloosa Plains, which comes with every building in the base game, as well as new stores and shops.
I find this expansion really fascinating, the interactions with your pets are great, and LOOKAUNICORN 8D!!!
But it's the expansion that may give you more trouble with graphics. Your pets can have all sort of deformation (some really creepy, other just subtle) even if you have a graphic card higher than the recommended specs (I'm not talking about the minimum one, you see) which may lead to some sad surprises as soon as you install it.
Other than that, it's really cute :)!