Hey, game author here! All the sprites are from an svg icon font and the rest is all just divs. My understanding is that the blurring has to do with how certain browsers handle 3d transforms by converting vector graphics into textures:

http://stackoverflow.com/questions/8024061/webkit-blurry-tex...

CSS transforms are awesome, but when you're doing crazy things with them things can get pretty buggy. Thanks for playing!