Firefox I got either no audio whatsoever or tuns of distortion, but it was otherwise playable. Microsoft edge couldn't get passed the load screen.
The raised buttons I could only really see when I was using mouse look on the actual square, so it led to a lot of moving one square, inspecting the wall brick by brick and then moving on. I'd at least make the the first one in the corner that the kid tells you about more obvious so people know to do that if it is the intended gameplay loop.
The music I think worked, but I definitely did get stuck some places for long enough that it got old, overall I think it definitely did add to the ambience though