FYI: the "turn" button has an "access key" specified ("e"), so it is technically possible to play via keyboard (assuming you know which modifier keys to hold down for your browser+OS combination). For example, on Firefox+Windows, I can hit Alt+Shift+e to rotate the snake.
And yes, having all the input round-trip to a data center in New York is annoying. But is it annoying as requiring JavaScript? ;)