First of all, i absolutely love this game. I think it's great that you get to do everything that you want in a Sims game, but you also get the added bonus of being able to share that with your Sim Pets.
The gameplay is smooth and very responsive, so your Sim or Sim Pet does what you want pretty much straight away, sometime if they are already doing something then they will do the task you want after that. The only problem iv'e had so far with gameplay is that when i bought a new house, it had 2-3 levels (downstairs,upstairs etc) and my Sims couldn't get into the house, and you couldn't look inside either with the camera, which resulted in me having to lose 2 levels of the house just to get in.
The graphics are crisp and there's a lot of detail to the items that you can buy and also the way your Sim & Pets look. There's also plenty to do with Karma powers, your pets also have wishes that need to be fulfilled so there's a lot to keep you busy.
Overall a very,very good game to not take seriously. Good for just having a mess about.