Also, if the browser's zoom is greater than ~200 the page size seems to infinitely grow - scroll bars appear on the right and bottom of the page and get smaller and smaller. The page goes back to its normal size when zooming back out.
There was also a black square in the middle of the screen but it disappeared. Assuming the border was misaligned.
Also, sprite font freezes the game, but I think Mipey said he's looking into that.
Using Chrome, latest version, GPU Accelerated Canvas 2D enabled.