I had a fairly enjoyable experience playing through my first game, untill I reached the end game and pollution made it's entrance.

Very quickly all of my cities were at 0% stability. due to massive pollution hits from districts.

I spent about an hour of gameplay trying to manage this new "threat" but no matter how many forrests I planted and how many national parks I built nothing made a difference.. I experienced crazy things like forrests disappearing from my buildqueues, and stability going from 100% to 0 and back to 100 canstantly jumping up and down in random cities all over the map.
Sometimes a city would be at 0% stability with no loss in ability to produce and build other non-stability structures, and then suddently the city loses population due to low stability. It's super frustrating

It definently seems like there is a huge bug in calculating stability once pollution rears it's ugly face.

I lost all interest in finishing the game, as the whole enjoyment of playing was ruined by this sad bug that messes everything up in the game.

It's sad to read that there is a known bug regarding pollution that is about 3 months old, and no effort has been made to fix it.