Among Us is the social deduction game that took over 2020: a crew of astronauts completes tasks around a ship while one or more impostors sabotage and eliminate them, and the crew holds meetings to vote out whoever seems suspicious. Innersloth released it in 2018; the browser version here recreates the ship, the tasks and the meeting loop so you can play the format without installing anything.
It is best understood as a browser take on the game rather than the official client — the official game is a paid download on PC and consoles and free on mobile. What this version keeps is the feeling: the map, the vents, the task list, and the paranoia of a meeting.
No — the official game is Innersloth's download on PC, console and mobile. This is a browser version that recreates the ship, tasks and meetings so the format can be played with nothing installed.
The browser version here supports the core play loop; for full online lobbies with voice and friends, the official game is the way to go.
The browser version does — it runs in the browser with nothing to install. The official game needs an install and is not available on managed Chromebooks.