the moon is not a spotlight, all the sand should have equal illumination due to the moon's natural lighting, also, you added too much haze and covered all the details within the sand
Well, I've made some changes .....
I gave a bit of texture and colors to the moonlight
I have a doubt on the perception of the texture of the sand
Any suggestions on how they could get a little more realism?
Thank you!
Maybe you could use more momplementary colors in the shadows versus moonlight - like you do in the foreground and it looks the best part of the image so far. Some reds and browns give scenery some shape and also gives stronger feeling to the blues.