Until Sunrise is a survival horror game structured around a single night: something is out there, dawn is a fixed distance away, and the whole game is the gap between the two.
The fixed endpoint is what makes it work. Unlike an endless survival game, there's a moment you're aiming for, which turns every decision into a question of whether it gets you closer to sunrise.
Survive from dusk until sunrise — a fixed endpoint, which is what distinguishes it from an endless survival game.
It's atmospheric survival horror rather than a jump-scare game, better suited to teens and up.
Yes — it runs in the browser with nothing to install.