Scene loaded fine for me. Although it was slow at downloading. Maybe the size is still too large. 6000x3000px should be plenty and you should compress this also. The audio could also be what's slowing it down. The audio was also extremely LOUD.
As for it failing on others, my guess this is other computers that had already attempted to view the "original way to large version" and now are calling it from cache. Either have them clear their browser cache, try with a different browser or rename the tour and offer a different link.