The problem is that the fish can easily get off camera, most likely crashing into another fish. This makes the game much less playable
I think the game screen does not fit properly on some mobile devices, but it definitely fits on larger screens e.g. laptops.
The WebGL build on the page itself has the display shaped like a mobile phone and I do not see a download link anywhere
I'm not too sure why the WebGL is not wide enough for you, but thanks for playing!