The source code is here and here.

I used the goog.History library and wrote a custom solution for loading pages. Each page is a component, and also the game page component has a subsystem which contains the game components. I have a div for each page and mount Rum on it when the component starts. The single-page app code is a bit hairy, especially some hacks to differentiate switching a page and figwheel reloads and avoiding infinite reload loops, and since only one page should be loaded at a time starting the system is different from the standard Stuart Sierra component library call to start the system. It seems to work fine now however, so I am leaving a potential cleanup for later.

Not much of a screenshot follows: Lobby