Jeg har en teori.

I suppose I should give a big chunk of credit to /u/zerogeekuk. Their comment (quoted in link) sparked a thought in my head and is basically the genesis for this theory.

Note: I won't putting stuff in spoilers. It's all dark and stuff. I can't even see where the spoilers are.

Anyway.

My theory is as follows: The NG ending is a ruse.

The important part of that quote is the mention of the movie Triangle.

SPOILERS FOR THE ENDING OF A FILM NO ONE WATCHED

The ending of the film reveals that the crew of the yacht are still stuck in the causality loop. Despite her attempts, the protagonist still ends up at the harbor shown at the beginning of the film.

So where does Oxenfree fit into this? Well, there are a few similarities and connections between the two.

1. The obvious: Multiple versions of the protagonist and her friends

In the film, Jess and her friends encounter many versions of themselves, with Jess inevitably becoming the killer first seen early in the film, and the others inevitably being killed off.

The multiple universe theory is essentially canon as of the NG version of Oxenfree. While in the bunker, Alex and Jonas discover that they can send messages to another version of themselves.

2. Triangles.

Well.

BUT.

If we're to apply the logic seen in Triangle to Oxenfree, what does mean?

Basically, Alex and her friends are, and are not, trapped.

As /u/zerogeekuk's theory states, each individual instance goes off and lives their lives, but Alex and her friends as total beings are trapped. Which brings us back to the alternate ending.

My theory is that Alex and her friends make it back to the boat no matter what. Which is what happens during some Strong, Silent Type achievement runs.

TL;DR Alex is, and is not, trapped.