

At the last second while holding his hand she sees his face for the first time and realizes who he is, letting him go and unwittingly committing him to his fate. Six is captured by the Thin Man and transformed into some kind of monster. Mono literally has a bag in his head the entire game for no obvious reason.

This is the only theory I’ve seen so far that actually makes sense and seems to be implied by the games narrative presentation. Their actions are a simple product of a never-ending time loop with no beginning. Which came first? You'd think Six dropping Mono, right? But why would she drop him if it weren't for the Thin Man? Six drops Mono because he's the Thin Man, and Mono becomes the Thin Man because Six drops him. Six letting Mono fall is completely reasonable - she thinks he's going to turn her into the monster! And then, Mono becoming the Thin Man is completely reasonable, because it's possible he never realizes why Six let him fall at all.

I thought it was actually a really good ending. Mono comes to the rescue, and again Six lets him fall because she realizes he's the Thin Man. Thin Man chases Mono and Six (Presumably for revenge against Six), abducts her, turns her into the monster, etc. Mono falls, and over time becomes the Thin Man. Six realizes Mono is the Thin Man then, and lets him go. That's when she pauses, and sees his face (probably for the first time, because he's not wearing a hat). They escape the Thin Man and run, jump - and Six catches Mono. Mono comes to the rescue, and there was a weird emphasis on not being able to have him wear a hat during this segment of the game. The way I interpreted it is the Thin Man abducts Six, tortures her, turns her into the monster, etc. She prioritizes herself above others, but is fully capable and willing of helping others. Six is an anti-hero, that's been pretty well-established.
