Agree with the others, continue! *But* if you ask me, don't be tempted to change the major details, the structure and layout of the scene, and the things that are already working, like the vegetation, composition, sky, etc. I feel like some pieces kind of "go off the rails" through additional tweaking, and this usually, in my view, occurs because people are tempted to change *too many things at once*.
Personally I think this needs *relatively* minor work from here. As others suggested, make the bumps and wear on the road more subtle and integrated, improve the models for the car and figure, fix up the road edge a bit (asphalt overlapping rocks, etc.), and give a bit more detail/texture to the large mountain shape(s) on the right. I'm not sure I would even touch the sky at all, I *like* the UFO being a bit subtle, and the large clouds add drama without losing that subtlety. It's really an interesting composition actually, I could see a real, historical UFO photo looking like this.