Undertale and Minecraft are two of the biggest "indie games" to make it big, both financially and culturally. People encourage their friends to get into both, not just because they're amazing (for certain values of "amazing") but also because they want to discuss these things with you, and they need you to understand their shared vocabulary in order to do so.
This shared vocabulary enables people to create art that can be widely understood and appreciated. Hence, the piles of Undertale fanwork, up to and including professionally-made musical productions; and the intricate Minecraft creations, up to and including Turing-complete redstone computers.
There are problems with this kind of cultural ubiquity, though. For starters, the amount of attention given to "hit games" literally starves others.
I don't just mean other games, I mean their creators. Creating art is only lucrative if you either get extremely lucky, or don't mind toadying to rich people. For everyone else, it's subsistence-level at best. And the systems we have right now are designed to ensure that this is the case.
Take the App Store as an example. Or Steam, or OneBookShelf's offerings like DriveThruRPG. None of these things are designed to help curate art, or earn attention for well-crafted games. Mostly what they do is ensure that when the next Minecraft or Undertale happens, the platform's owners get up to 50 percent of its earnings, as in the case of OBS' licensed "Dungeon Masters' Guild." They take zero social responsibility for everyone else, who basically work "on spec" in the hopes that somebody will notice them.
Actually being noticed is a full-time job. There are social circles you need to be in, communities you need to be part of, and norms that you need to adhere to. Even Undertale is both visually and thematically a tribute to the Mother (Earthbound) series of cult-favourite JRPGs. Fail to create your own cult, or pay tribute to an existing one, and you're out of a job just the same as if you get fired from full-time employment. Except that when you were employed, you probably had medical coverage.
(It's one of the only reliable ways to access health care, here in the States.)
tl;dr I'm bitter about my fanfiction not being noticed, and should probably just learn to write stuff others like. Damned if I'm not saving *Mute first, though, and damned if I'm giving up on writing meaningful things for underserved minority groups.