There was a fun hacker news post a while back [0] about a website that had generated every solvable-without-backtracking 5x5 nonogram. I found it very addictive, and the creator has since released it as a paid mobile app. Highly recommended for commutes!
I really didn’t expect to get a new favourite game of all time in my 30s, surely the nostalgia factor was too strong, but Outer Wilds was exactly that for me.
It still doesn't sound intentional to me. How many scammers are going around creating useful apps, supporting them, pushing out new features, and then finally doing the rugpull 14 years after release? It feels a lot more likely that the backend servers have fallen down on their own and for whatever reason there's no one around to fix them.
I also never see this behaviour, but I pretty much only use the tube for commuting at peak times. I think commuters are generally better behaved. The sheer density of people means that anti social behaviour will get angrily shut down very quickly.
[0] https://news.ycombinator.com/item?id=44140918