I have been having trouble getting the WebGL optimization, I might try a different compression mode. I've had mixed results of people able to play it on Browser and not able to. Are you using Chrome by any chance?
I just uploaded the proper Downloadable build, let me know if that works if you want to try it. I'm sorry you aren't able to play it! That's one of my fears is others not being able to enjoy it after going through the trouble of finding the page.
It does sound like an optimization issue if it's running at 5fps. Again I'm really sorry and I'll let you know when I update the webgl version. Thank you for at least trying!