Trying to write about Space Station 13 is inevitably a complete nightmare, as by the time you've explained what it is to any degree of adequacy, you're approaching long read territory. But since this is a cheery little "hey, check out this interesting game" post, I'm going to try it in 100 words. Let's go.
SS13 is a top-down, multiplayer, session-based RPG, where people take on jobs aboard a space station, and can interact with everything therein. It was originally a sober atmospherics sim built in freeware engine BYOND, but after the code became public, it... evolved. These days, SS13 exists as a spectrum of wildly different, community-run servers. Some are semi-serious roleplay environments. Some are anarchic. Some don't even feature space stations. Most are "hidden traitor" games, but they all share two things in common: they're a pain in the arse to play, but it's worth it for the stories they generate.
There you go. Had to hyphenate a bit, but that's Space Station 13 in 100 words. Honestly, though, I could have used 10,000. The sheer convolution involved in the game's 17-year history, plus the sheer range of totally different games which come under the SS13 title, is worth a decent YouTube documentary or three. I'm sure they exist; you should watch them. But to me, I suppose, the real joy of the game is in the way its maximalist, 'anything is possible' immersive sim ruleset combines with the creativity of a player base committed to really weird, inventive roleplaying.
It's a genuine struggle not to just break into a breathless account of the many ridiculous scenarios I was lucky enough to be a part of during my brief year or so playing. But if I started, I'm not sure I could stop, so once again I will implore you to seek out some of the many, many SS13 anecdotes floating around online.
I said the game's player base is committed, and I think that's the secret ingredient in SS13's unique, ridiculous beauty. It's just not a game you can just blunder into, after all. At least when I got into it, at the start of the 2010s, you had to jump through a lot of hoops just to boot up the game and join a server. Then you had monstrous lag to contend with, not to mention the byzantine horror of the interface. The learning curve might as well have been a granite wall, even with recourse to server-specific wikis, and so if you stuck around long enough to achieve anything like mastery, it'd be because you were determined to go all-in on collaborative weirdness.
Despite endless chat about sequels and spiritual successors, I'm yet to see one properly emerge. There are excellent games such as Barotrauma which have definite SS13 DNA, but there's still no game out there that is a straight up remake. And maybe that's a good thing? As bizarre and inaccessible as it it, I think Space Station 13's magic comes from the very factors that hinder it. If it was reasonable in any way, it wouldn't be Space Station 13.