Yeah, those seem to be the preferred alternative bindings for rotations. You can set it to the left/right arrows, but then you'd have to write "arrowleft" and "arrowright" without being able to actually write the 'a' or 'w'... While you can copy paste it from somewhere else, those setting are far from ideal. The reason why the game "takes" all the keys used is so that, for example, pressing space doesn't move the page all the way down, or the up/down arrows don't move the website... I guess there's advantages and disadvantages to web games like these.