I have quite a few bugbears with this film, while the acting is okay absolutely no one could make you believe any of these characters were actual people. They don't interact like normal people, they don't converse like normal people. Kostis goes from seeing guys his age chasing young girls as odd and not his thing, to not only doing exactly that but going a million miles further. The idea that Anna and her friends would take any interest in the dullest man on the island being their friend when they're so clearly about living life to the fullest, is hard enough to believe. There are a couple of scenes that just seem to be in there for the sake of looking good, which yes they are pleasing to the eye but that is all they offer. The film does feel very ponderous, in another film it might be ok to have extra scenes for artistic value whereas in this film you just wish it would pick up the pace.
The ending is a weird choice, we've witnessed a guy who in the beginning you feel does have a sense of morality and is maybe a bit weak willed or caves in to his infatuations but as the film goes on he just behaves worse and worse yet at arguably his lowest point that is where he draws the line? To that point he's been so weak and easily lead into being a terrible person, he's even went more than halfway through a very disturbing plan. I guess you could say he eventually broke or reached his limit, but to end there... there is no redemption for the character, there is no apparent consequence for his actions.