The idea itself seems nice, but it remains to be seen how useful it will be beyond learning basic language concepts and syntax.
However, I would like to compliment your website. I run an extremely restricted browser that blocks most JS, cookies, XSS, etc. by default and most new project announcements I see on HN I close immediately because they haven't demonstrated enough value for me to bother unblocking the ungodly mess of JS on their sites. Your site isn't just well designed, concise and readable, it actually works out of the box (the only thing I blocked were the social buttons), barely uses any resources and looks lovely. I wish more web developers thought this way.