My focus went immediately towards the screen in the center, since it's bright color stands out from the darker surroundings, and I could immediately recognize the invaders, and it definitely threw in a spark of nostalgia in my mind as well. :3
The overall choice of colors is really fitting, but I think you could have added a lot more detail to this to improve it. The walls and floor feel very dull with just the simple single shade of gray to them. You could add some texture by simply adding a second slightly darker or lighter color to the mix with some smart dithering.
Most of the objects are really nicely rendered, and they are easy to see what they portray, but a few of them look a little odd in my opinion. The broken "thing" on the right edge of the image, what is that supposed to be? And at first, I thought that thing hanging on the wall above the screen was a hammock or something, but now it looks more like a flag, or possibly a towel, to me. What is it really?
Overall, though, it's a nicely made piece, but it could use a little bit of work.