i just tested out your map and i have some feedback for you:
the map theme is just too simple. in my opinion, i think that you should elaborate more on your theme, as simply building two islands is just much too simple.
i really dont think this map fits a medium or hard. im not the best at parkour, but this map was still fairly easy for me. also, i was quite confused at times about where to go next, so i'd suggest making the signs with instructions more noticeable (for example, one was hidden on the side of the island, and it took me a while to find it).
the parkour just felt a bit dull, and there just didn't seem to be much to it. but nonetheless, i wish you good luck !
happy new year :)