These drawings remind me of the concept art for Crash Bandicoot, with a night and day version for each type of level. Granted your style is more realistic as opposed to cartoonish. :P

The brickwork of the path is really well done as well as the dirt walls. Only thing I can point out is the vines on the broken column closest to the left side. I could be mistaken, but the vine you drew traveling upwards looks a tiny bit too similar to the grass on top. Changing the vines colour to a slightly different shade of green would make the vine stand out more. However, it could also just be more grass, in which case I AM in fact mistaken.

Excellent work overall!