Chromium: Arrow keys did not move snake.
Firefox: Nothing showed up at all.
No, I'm not running tinfoil hat plugins like noscript. These were vanilla browsers.
Things are flooded atm. Trying to resolve.
Uncaught RoomSizeError: Room is full
Problems seem to be server side, too much load most likely. The browser side seems fine, sends requests, but the server (goinstant.net/engine.io) is not responding. So not a browser compatibility problem I am guessing.
It was reasonably quiet when I was playing, but a couple of times it looked like the thing you had to collect with your snake respawned on the other side of the board before anyone could conceivably get there. Was quite irritating.