Works for me, v75.0 (64-bit) on MacOS Catalina. You were probably experiencing the hug of death.

yep. opening in FF 75.0 on Linux shows a white blank page. Opening in chromium renders properly.

Looks like it's three.js failing to initialize webgl in firefox. Probably some firefox webgl issue.

Same here. Broken on FF 75, works on Chromium 81