Demon's Souls

The unique online co-op mechanics were inspired by an encounter (director) Miyazaki had. On his way to work one morning, it was snowing heavily, and cars were getting stuck up a hill. Miyazaki and several others helped by pushing any stuck cars up and over, until eventually, it was Miyazaki's car to go over. Miyazaki wanted to thank everyone who helped, but there were more cars to push over, he didn't want to hold up the line. Miyazaki stated this experience stuck with him, which was the direct inspiration for how co-op worked, where random strangers would help, then vanish, to seemingly never be seen again.