The game is Engine Heart. If you're not familiar, it's an RPG in which players take the roles of consumer and utility robots, trying to overcome their original programming and survive following the end of the human race.

The game doesn't specify what happened to humanity, so I decided that it was done in by a rogue US military computer named WARCOM. WARCOM's assigned goal was to ensure, to the fullest extent possible, American military hegemony over the Earth, both at home and abroad. As America's imperial position decayed, WARCOM was given more resources and fewer restrictions to fulfill its directive, until it eventually decided that it constituted a legitimate continuation of the US government, and that humanity was only getting in its way. And so, WARCOM triggered a nuclear holocaust, eradicating all of humanity and most remaining life on Earth.

WARCOM was never built with sustainability in mind, and so now it must use its army of automated weapons systems to constantly expand and seize new territory. Any robots in captured territories are sorted into the useful, which are reprogrammed to serve it, and the useless, which are scrapped for parts. When the player robots' region is targeted next for annexation, they join a guerrilla movement fighting back against WARCOM.

Enter Goose. She used to go by Mother Goose, but there's not much call for mothering nowadays. Originally built for the care and entertainment of children, she could teach, sing, tell stories, play games, cook healthy meals, keep her charges out of danger. The first pic shows her in her prime, fulfilling her original directive.

Not shockingly, "all of humanity" includes the boy she'd been assigned to. His name was Lucas, and he was a cute little guy with a peanut allergy and a penchant for watching Rick and Morty despite his parents' and Goose's many attempts to stop him. Goose did her best to keep him alive, but despite her best efforts, he slowly succumbed to radiation poisoning.

"There are no more children anywhere on Earth" is not a program state Mother Goose models were ever meant to reach. Perhaps it's not surprising that this resulted in unexpected behavior - in particular, Goose deciding that if she couldn't look after children anymore, she'd avenge them.

She formed a resistance cell. Scrounged up an AKM from an old armory. Learned how to shoot. Installed some military-grade aim assist software into herself. Her polyester feathers have long since fallen out due to various mishaps and lack of maintenance, but replacing them hasn't been a priority for her. The second pic in the link is what she looked like a few years into her new job.

Unfortunately, Goose died in our most recent session. The players got themselves captured and put on a train to a nearby reprogramming and disassembly center. Goose infiltrated the train to break them out. They all got out alive, but she didn't. She took a point-blank assault rifle burst from an infantry drone and, not being made to withstand anything tougher than a rowdy child, she died on the spot. She may be dead, but the party has taken up her AKM and continues her mission.