I sat staring at this for a good while as there is just so much to look at. The use of line to create uneven roughness makes the background look almost tangible. The color scheme is well thought out also. The horseman's outfit being made up of the same colors as the three frontsmen add a bit of irony and humor.
I think the legs on the pink jeaned lady are too thin. They almost look sickly.
Also, the area of background between the horse and rider is a little confusing. I'm not sure if I'm looking at trees or rock, or both.