Not bad for a minimum layout. A couple of suggestions:
1- Put a little more space between the cross over turn outs at the top. This way it could be used as a run around.
2- a couple of more sidings for more industries would make for more interesting operation. One could go from the bottom right and turn in towards the center of the layout. Another could use the space between the inner and outer (in tunnel) lopps on the left side.
With SCARM toy can explore all sorts of possibilities.