This is good, it's a bit short, but given that you tried a 3D game I think that totally makes sense. I liked the atmosphere too, it kind of reminded me of Antichamber at the start. The controls and performance were also good, so I can see this being a great foundation / template project for 3D movement and interaction in your future games.
One other thing, I found that my mouse was perpetually focused into the game window after I clicked on it, and it wouldn't stop moving the camera nor could I see the mouse after hitting escape and exiting into windowed mode. So I would suggest adding a 'uncouple the mouse from the camera and show the mouse cursor when the player hits esc' functionality to improve the browser experience. Very solid work though!