It looks great, most of the time. BUT, certain versions of Internet Explorer (9, i think) show the game canvas as vertically squashed.
Is that only when it's embedded or also in fullscreen? Anyway, IE 9 and 10 doesn't support webGL and are not fully compatible with html5. First IE11 has webGL support and a higher html5 compatibility.
I tested your game with IE11 and it looks fine. So, I wouldn't bother with older IE. If it's not a problem with the embedding in the side I think you can do very little.