I experienced a lot of weird glitches during the cutscenes where only a portion on the screen was actually displaying what's in the game in the browser (full screen) but then it worked ok.
During the gameplay - I'd suggest to tweak a bit the clipping/culling of objects. the camera was constantly in the walls which is not pleasant. You could probably force the camera to always look towards the fish from like middle of the room. That would solve this issue and could be actually interesting gameplay element.
Great story 10/10. Rip Steve. Long live the fish