Hi guys i am doing this work, basically the idea was to create a kind of retro and vintage style. What do u think about the image, and what could be improved? i don't know how to post the image so i leave the link bellow.

Nice image, Love the models face contact...very engaged.  Nice location.

There is one element that concerns me.  There is a deep lack of contrast in the rear of the image on the games...all of the normally black parts of the image have been lisfed up in contrast to the blacks are quite grayish.  This looks unnatural for me...and it takes some interest away from the girls...because it draws my attention from them to examine the unnaturally low contrast colors in the back.

I might consider blurring the background slightly to make it compete less with the girls...or maybe do a negative curve or levels and darken up the background so it doesnt stand out so much.

Retro images sometimes have a more magenta toned skin color or more of a brownish cast.  Your skin colors are pretty modern and dont illustrate the bad color shifts images sometimes had in those days.  Do an image search in Google and type in "retro looking images" or some other phrase like that in the search term.  You will see hundreds of retro images.  Begin looking at what colors, or characteristics, or stylistic elements seem to pop up often in the retro images you are looking at.  Then begin replicating those very same colors, contrasts, edges, saturations etc in Your Image.  Train yourself in what real, actual retro images looked like...and then shoot in those kinds of locations, with those kinds of props, and those kinds of clothes, and those kinds of makeup and hair styles and lighting and processing errors and edges etc.  Pick out what characterizes that period...and then make sure you include some of those same characteristics in your original photography and post processing.

9/10 very natural and good pop of colors