Hmm I know peeps are talking about the jumping thing alot already. I don't know if you guys figured it out but I think the issue is the player's speed/velocity isn't being applied by Time.deltaTime properly. So when the framerate is very high on a good machine it works great. But when the framerate gets lower in a WebGL build, you can't jump as high anymore. On my older machine at 5 frames per second I jump about half as high as on my other machine.
Really nice graphics and audio!