I wouldn't say "changed my life" but the Cassandra ending to Mafia 3 is pretty fucking grim.
The government gives up on the city and cuts off all funding to school, police, road maintenance, electricity, garbage disposal, everything. A hurricane comes by and they also offer no help, leaving the entire city to die.
It was quite the left turn from "I just got my revenge and I'm driving out of town in my cool car while listening to some quality music".