Yes, you're right! To quote the page description:
"...In June 2017 Dan Sanderson published a micro horror game on itch.io called Pacific which, to his surprise, was picked up and praised by popular horror YouTubers such as MrKravin, Markiplier, John Wolfe, GirlGamerGab and RaedwulfGamer. Enthused by over 1.5 Million views and featured in Waypoint Vice and IGN's '12 Awesome Games you might've missed', First Winter was born. First Winter is a remake/sequel to Pacific and continues the theme of nuclear war."
Glad you got to play Pacific too, so you could see where it all started!