I played all the way through (I don't want to mention my score). It might be your browser - I'm on Firefox and it worked just fine.
Oh, so it takes minutes or hours for it to be ready to play? I wish I knew that...
No, he's talking about the update time. Yes, sometimes when you post a game they update instantly. Sometimes it can take up to a day. I've learned to put version numbers on my front screen so I can tell when it updates.
I've noticed that the http version of the site responds to new uploads and reuploads much faster than the https version.