Oh sure, there's certainly more explanation that deserves to go on the game page, but here's the personalized gist:
It's a rhythm-based music trivia game (in this gamejam-specific iteration featuring a whopping 1 Iron Maiden song's chorus) where you're trying to pick the correct words to fill in the blanks in the scrolling lyrics. You've also got a constantly depleting stamina meter that you need to keep replenished by timing your A-B-C-D selections with the arrow zipping across the screen so that those "?" blocks get hit by your click. Thanks for giving it a spin! :)
Ah jeez, that's an unfortunate bug! Sorry about that but cheers for the heads up. I haven't been able to reproduce it in Chrome but there are definitely some quirks I've seen machine to machine with this web version that I'll be looking into. If you'd like to give this a proper try and have something running Windows, the downloadable EXE should perform much more sensibly :)