Maybe it was the Firefox addon Canvas Blocker? That addon was crashing the game, so I disabled it and appears to work now. The game still makes my laptop fans kick on though.
The game is only able to utilize one CPU core when running in the browser, maxing that core out probably set off your fans.
https://github.com/golang/go/issues/28631
The game is only able to utilize one CPU core when running in the browser, maxing that core out probably set off your fans.