The softness look comes from the shading, since you said you wanted rocks, and not dirt, which is what it looks like now (and pretty good btw), then you need to define the edges of the rocks more, leave abrupt edges on the rocks where the light won't hit, 'rocks' are usually thought of as more jagged than smooth. (However they can be, it's just about the style you're looking for, I believe making them more jagged would give them that 'rocky' look.)
Also, I'm not sure about that dark red (and gray!?) for the bottom of the mountain, I don't believe it's helping the piece, maybe you should go a lot more towards dark brown, and define it a little bit more down there.
And it looks like your light source is coming directly from the top-center, so, the sides of the mountain should naturally be a little more defined (lit up) than the side that is facing us . I think you would benefit from moving it a little (or a lot) to the left or right as well, as thing generally look more interesting, and it would probably help in removing that soft, 'pillowy', look as well.