I managed to get this working with window.AudioListener.prototype.setVelocity=function(){} and WEBAudio.audioInstances[channelInstance].panner.__proto__.setVelocity=function(){} - both typed into the web console at the right place. Not the best fix, but it at least gets into the game. The alternate method is using Pale Moon.
However, the game still glitches. The most important bit is that it dosen't capture keyboard/mouse properly. When I did get that working, the farthest I got was in the first map, just before building blocks to the final platform, before the browser itself crashed.