Doki Doki Literature Club is the only viral game I really got into. But it's less a case of just playing the game over and over, since DDLC is really a "play it once and you're done" kind of game. DDLC is more just a sub-culture at this point where the fandom has sort of taken off with it and is making all of their own merch, game mods, and fan art and music inspired by the original game. It's why the game is popular at conventions when it comes to art prints and the like. It's even inspired people to take up poetry (I've been considering doing this myself, since I used to like writing poems for English class).
Most people are beyond done with talking about the game itself, it's more just filling your feeds and what not with DDLC content made by the fandom at this point.
I think this is part of the reason why the DDLC fandom doesn't really have any toxicity. Most people who love the game love everything about it since it's just a game about these four (or five, counting MC) characters. While in something like Fortnite or Minecraft, players are interacting with each other which breeds toxicity, and Fortnite encourages a really competitive mindset that often leads into toxicity.
It also helps that DDLC deals with difficult subject matter and people have been brought together by that.
r/DDLC is my favourite subreddit primarily because it's so laid back and everyone is nice to each other. And it's super active so tons of fan art and cosplay and stuff gets posted.