hi Plinkr, I discovered something you may be interested on. Shaders do work perfectly well on Arm as they are, the problem is with sailfish os which may use an older version of opengl? I don't know the reason but the game works with all shaders on Postmarket Os (althoug performance suffers a lot).
I added a video showcasing the optimizations I added for mobile phones. I fundamentally reduced resolution to 20% and this way it render fast and with all effects on mobile phones.