It feels weird. When the game ends because of rising pollution levels, is it really considered a win?

I don't think excess pollution is a win? It just makes the game end early, and whomever has the highest fame at that point is the winner.

It's considered an ending condition. I agree that it's definitely not the best, you just managed to kill earth, but while doing so, your civilization was the "best".

Right now you gain fame for being a major polluter, losing fame would not fit the game as fame can only be earned but never lost. Keep in mind it is not always advantageous to end the game as you may not at that point be leading in fame and thus may lose the game. Also pollution do give a massive local penalty if you produce more than 10 per turn in a territory, with -50% to all resources produced by districts except industry and -15 stability per district, meaning it is generally a bad idea to build stuff that cause pollution without having good pollution reduction, except if you look to end the game quickly as you will probably hurt your economy more than help it.

I think when the game ends because of high pollution, I think it should count as min points towards everyone's fame to ratio. So the one who polluts the most, will get the biggest penalty and so on. (of course, this could be an optional function you set before you start. Not everyone will think environment is important, but I do haha.

(Yes, I know the game does not give penalties for Fame. But penalties wouldn't be that bad. If I surprise war all the time, well, that could be penalties as well if you ask me. Cause it makes me infamous)

Pollution still triggers major penalties on your cities. So if you still manage to be on top while being the biggest polluter,it think that's "ok".

Agree there should be fame rewards to counteract pollution, maybe things such as ban fossil fuel, can no longer use coal at all, all coal power plants are dismantled and can not be built, electric bonus is lost and so on.

But I would avoid someone to get pollution AND anti-pollution fame at the same time!

Maybe the academy quest of ES 2 could be a way to do that, but seems a bit too manichean for Humankind maybe!

Yes it could be an issue, however if you go pollution and then anti pollution you would lose much of your infrastructure investment if you must remove all pollution infrastructure.

It's not technically a win.  The end game conditions are precisely that, they end the game.  Whoever has the most fame when the game ends, wins.  Everyone contributes to pollution.  If you happen to be in the lead when it hits the tipping point, you win the game.  It's just a gauge of who will be the most remembered culture in history based on their deeds, doesn't mean its a good thing, people get famous for bad shit all the time.

The biggest issue seems to be that the AI has no idea what to do with pollution. They just build and build and build.  It doesn't seem they factor in the game ending at all - they're more than happy to charge right on ahead into a game ending level of pollution even though they're not the fame leader.  Also I don't know that the AI factors in the territory penalties either.