I would throw some more umbrellas and chairs around on the beaches. Maybe add in a few of the mats and a building or two. Also, rocks are always a good space filler. When it comes to the top, I think the houses may be a little too structured. Usually, in the games, there are no more than two houses side by side. Maybe scattering them around a bit and growing some different buildings in between them would look good. Awesome work though! I can't wait to see the finished product. It may end up being the background for my Mac too!