Oxenfree is more an interactive story rather than a video game. Sure, there are elements of a 'gameplay', but for the most part, you will be working out the story and not worrying about the game. This post is heavy with spoilers, so if you need a shorter reaction - I liked it very much, thought it was AWESOME, and so you should go play it.
Now that we can continue, let's delve proper and deep into the game. Oxenfree is about a bunch of school kids who sneak onto an island one night to party (read drink alcohol and do other teenager things). The primary protagonist is Alex, a blue-haired girl. She meets her half-brother Jonas and her best-friend Ren on the last ferry to Edwards Island, where the game takes place. The gameplay follows the characters speech through interactive bubbles that popup on top of Alex. Most of them have the form of a choice, where the selected bubble makes a difference in how other characters view and feel about Alex, and affects the later parts of the game.
Once started, I immediately felt a distrust towards Ren, who insists on checking out some shady caves with elements of supernatural thrown in. But as the game progressed, my suspicions were instead turned towards Jonas, who had just turned up from nowhere. The fragile relationships of teenagers is well captured within the game, and for once, the story felt satisfying. Most of the game is about discovering the phenomenon on the island. As soon as things start to feel monotonous, there is enough variation and science fiction thrown around to make it very interesting. For example, the way time loops work in the story line is pretty amazing. The horror and creepy elements also work well.
Perhaps the greatest strength of Oxenfree is its lack of cut-scenes to progress important information and elements of the story line. The gameplay and conversations feel free (even though they are not) and the story is quite well set. My one beef with the game was its ending - I did not like it. I got the 'goody-two-shoes' ending, which meant everyone was saved and the ghosts, or whatever beings they were, just left. I later found out that this was one of the possible endings. The other, and more likely, ones were far too realistic. Which included leaving one of the other people behind, essentially sacrificing them or sacrificing yourself.
Overall, I think the game deserves the high praise it has received, and I will be recommending it to everyone. Takes about 5-8 hours in a day. So a weekend adventure.