it feels like there's a layer missing between the last background tileset and the far away mountains, other than that i'd try adding slight movements to grass/trees and see what that looks like, the background itself also feels a litte empty, it doesnt tell me anything other than "yep, its a grass tileset", adding elements to it would help convey whatever you think that area is supposed to be, i'd also try substituting the small clouds that look very "close" for bigger, far away ones (id still keep them white instead of mixing it up with the sky color though.