Not perfect, but how can I 
It seems very odd to have a clean, green refrigerator in there; maybe it should be rusty and yellowed with thick dust or something. Also the oil drum closest to the camera seems to have a worn blue paint and plaster material. If you zoom in on the rocks they lack detail; DOF might help with that. And the floor’s normals could be a little softer I think. You might try adding a rusty bicycle at the back wall (it feels empty back there).
Just throwing out some ideas. It looks really great how it is though! Keep it up!
The refrigerator could potentially work well as a contrasting element in the scene. However, it perhaps sticks out a bit too much (which is more so in the full-size resolution).
I’m not suggesting it should be in the process of falling apart or corroding away, just have it a little more integrated.
Thanks for the advice, they are always very important)