C++ to JavaScript!? Unpossible!
Even I don’t believe it myself.
So I did a writeup about the blasphemy I did last weekend: Creating an HTML5 (JavaScript) game in C++. You can read it here:
http://www.toonormal.com/a-technical-look-at-c-gamedev-in-the-browser/
Also, there’s a newer “Post Compo” version of the game out now. There’s no new content, but it should run better for everyone.

NOOK - New Post Compo 60 FPS version
So ya, maybe HTML5 isn’t as good as Flash yet, but it’s getting there. 
EDIT: Oops, Ludum Dare link is here, just in case you want to rate it: http://www.ludumdare.com/compo/ludum-dare-23/?action=preview&uid=19
1. Because to me working in javascript is a royal pain, I can fare more efficiently write C++ code than javascript as the language just “clicks” better for me (that and 10+ years of experience in it doesn’t hurt)