How did this game get so big so quickly?

I've seen games rise on the internet suddenly (Rocket League, Fortnite, and now Fall Guys). Most of them I understood. But Fall Guy, not so much. It looks incredibly fun, but I haven't had time to play it after buying it yet. So I watch Twitch etc for passive entertainment while working.

But how did this game get so big? Was there one YTer or streamer that played it and boosted it's popularity? Was it advertised heavily? Was it featured on some other popular show? It's kinda like Mario Party, which is an excellent game, but never achieved this level of streamer/internet hype popularity. I just don't get it!