Presumably his is inside a cave with a chasm in the middle. The problem for me is using the same texture for the cave walls and for the chasm. Personally I'd make the chasm black and have the shadow hide the ink edges of the chasm walls so that it doesn't look like it has a floor. The way it is, seeing the outline of the chasm makes the chasm look like a floor (if that makes sense). Other than that, stellar job, I love hand drawn stuff.
Also for your walls, consider having some free floating ink lines, they dont all have to connect (and looks better if they dont imo). I don't know if it's supposed to be a slope leading into the chasm, but having the walls extended so much (beyond 1sq) makes them look like it slopes into a chasm as opposed to being a chasm at the edge of the ledge (ie. it looks like I could walk on the chasm walls). The narrower and tighter they are to your ledge the more steep the walls will look.