Nice work overall. That was fun.
Just a heads-up though: There are some typos and grammar mistakes in your explanations, so if you plan to share professionally, you might want to have someone proofread it. Also, your Facebook OAuth window that pops up upon page load is being caught by Chrome's built-in popup blocker. Either way though, I'm always disappointed when Facebook OAuth is the only login method. I get that it's easy to implement, but I can't imagine this is a very security-sensitive app in terms of user-accounts. I would like to save my progress, but it's not worth the risk or analysis required to hook up my Facebook.