Small Games, Big Hit

[GamerInGeorgia]

There are many games that are made by many people, but small development teams rarely hit the jackpot with the gaming community.
Nevertheless, there are games created by indie developers, and the like, that go viral (i.e. Undertale and FNaF). What games do you know of, or have played, that were created by small indie developers that have become a big hit in the gaming world?

Here, I'll start:
Bendy and the Ink Machine by 'the Meatly"
It's about a guy named Henry who is called back to the old animation studios by his co-worker Joey Drew, who wants to show him something. Henry arrives, and can't find Joey anywhere, but while poking around, he finds "The Ink Machine." What else is there to do, but turn it on?
The game is episodic, and Chapter 4 is currently in development. (The first chapter is free, though.)

Doki Doki Literature Club by Team Salvato
Note: The spoilers are there for people who want to play the game blind.
Rule #1 for this game is "don't judge a book by it's cover." While it might seem to be an average visual novel game for the first chunk of the game, the "Psychological Horror" tag on Steam says otherwise. After a few days in the game, the strangeness begins with a JPG file being created on your computer. That's right. The game literally puts and deletes files on your computer. (Only game related files inside the game's file system. This is not a virus but a gimmick of the game.) Then one of the characters

Spoiler

commits suicide,

and the game gets more disturbing as you go, as if the game itself is breaking apart, and, in the end

Spoiler

one of the characters becomes self-aware, falls in love with YOU, the player not the character, and literally deletes the other characters' files.

Sadly, it takes time to get to the juicy stuff. So you'll be doing a lot of skipping around. But, the good news is, the game is free! So go play it if you want. Or watch a YouTube play-through. The choice is yours to make.