Game does not work on Firefox.
Viewing post in JS2k - NES Ghost blaster jam comments
Unfortunatly, it uses `new OffscreenCanvas()` for sprites. It's syntax can be compiled down to a smaller footprint than `document.createElement('canvas')` and it's much more performant too. https://caniuse.com/#feat=offscreencanvas
Adding support for firefox and safari would require some effort. I'll see what I can do.