I found a glitch: when on the y2k or 1998 control modes, and you press space + arrow keys (not wasd), it will move the tiles by two spaces instead of one. Also the intended behavior of the arrows in these modes is not really documented. I think a more convenient control scheme might be to allow the arrows to either flick+move or flick in-place depending on space/another toggle button.
Another minor problem, in the browser the esc key exits fullscreen mode, so it isn't ideal as a "back" button. Maybe add an alternate back button (I like z/x as accept/back)