removed box2d examples
how did that get in there?
removed unused sounds, tidied up sounds.js, extended hearing range for sounds
removed mention of unused sounds, removed last modified thing
trying out 64x64 tiles
tweaked level rendering to reduce cpu usage
made the aliens a bit smaller
made the text a bit more legible
can now render multi-layer maps, with different tilesets, but no parallax yet
still can't get parallax right