When I load it, the website states that the simulation does not work on Firefox + Linux. Works fine for me when I re-opened it in Falkon (WebKit-based).
Edit: another responder to the parent comment said it works for them on Firefox dev edition on Arch Linux. I'm using Nightly on Arch and it gives the message stated above. With a UA switcher set to Chrome Windows, it loads but renders the image strips on the map as black stripes instead of 'textured' ones. Interesting...