• Ring of Pain is a great roguelike.
• Paradise Killer - Not actually sure how to describe Paradise Killer, but it’s one of my favourite games.
• The Red Strings Club - Interesting, short and sweet
• Stephen’s Sausage Roll - If you love puzzle games and can’t find any that are hard enough for you, it might be the best game ever made. Or the most infuriating.

And then a few that maybe aren’t that obscure by now, but I can’t not mention them

• A Short Hike - I think possibly the greatest small indie game of all time? Certainly one of my favourites.
• Baba Is You - (slightly) less extreme puzzle game, but it’s also great.
• Inscryption - Just a great game, can’t say much about it without spoiling the experience

• CrossCode - Phenomenal action RPG. Combat is fast and explosive, dungeons are very obviously Zelda inspired but with way more puzzles. Packed with tons and tons and tons of sidequests, many of which put unique twists on the combat system to keep you on your toes. Make sure to grab the epilogue DLC.

• FOOTSIES - Minimalist one-button fighting game, with rollback.

• OneShot - Fairly reminiscent of Undertale, if you liked that you’ll probably enjoy this too. And like Undertale I don’t want to say too much, take my word for it and let it surprise you.

• Petal Crash - Absolutely fantastic versus puzzler, and a perfect entry point into the genre. I wrote a very long review of how in love with this game I am, so I’m just going to link that.

• Them’s Fightin’ Herds - Another great fighting game, been waiting a long time for this port to bring us up to a grand total of two good fighting games on Linux. Has a lot of really cool features like a big story mode with overworld exploration, a cute lobby system with cosmetics to collect and treasure chests to fight for, a dynamic music system that reacts to the fight, and even a semi-cooperative dungeon crawler mode. Has crossplay with consoles as well. Full review.

• Ultimate Chicken Horse - Start on a nearly empty platformer map, each round everyone adds one object somewhere on the map then you all try to finish the level. Whoever finishes gets a point, plus bonus points for whoever finished first or collected coins that have been placed. Then you add another set of objects and repeat. Quickly becomes hilariously chaotic as you try to figure out how to balance screwing everyone else over while still making sure you can win, only to realize that after a few rounds you have all built a horrifying monstrosity. Has full crossplay with console versions.

• Anything by Zachtronics - A bunch of different engineering puzzle games where you have to write code or build a machine to solve problems. Once you’ve solved the puzzle, you can see a histogram comparing your solution to everyone else’s on a few different metrics, encouraging you to go back and try to optimize it further. I recommend Opus Magnum as the best entry point.

You’ve already got a bunch of great suggestions, but I’ll throw my two cents in too. I think of these as indies or games that have a niche audience, but some of them probably have bigger teams involved.

• Outer Wilds. It’s a quiet, contemplative game about space exploration and seems unremarkable until you really start exploring and learning about the solar system you’re in. If you play it, go in blind. IMO it’s a perfect game.
• Pentiment. You play as a young artist visiting a Renaissance-era hamlet to work on your masterpiece. The game is gorgeous and thoughtful about the decisions the player has to make when spending time and influencing the narrative. Stayed with me long after I finished.
• Slay the Spire. Tightly-balanced deck builder rougelike. I’ve put untold hours into this one on maybe 3 different platforms?
• Wildermyth. Hard to describe this one–it’s like an interactive fantasy tale with characters that grow and evolve in ways you won’t expect, and dynamically told so no two stories are quite the same. Pretty solid combat mechanics, too.
• Undertale. Does Undertale count as relatively unknown? If so, Undertale.
• Case of the Golden Idol. Very good mystery game with a cool, novel mechanic for solving each mystery. Don’t let the aesthetic put you off.
• Return of the Obra Dinn. Another incredible mystery game where you are determining what happened to the crew of a ship that sailed into port with no one aboard.
• Papers Please. Simple mechanics that really make you FEEL like you’re -Spider-Man- an oppressed civilian in a fascist/totalitarian government.
• Disco Elysium. Another great mystery game, wherein part of the mystery is: what kind of person were you, and who are you now?
• Tunic. It’s like old-school Zelda but with more depth and some serious twists.
• Stanley Parable. It’s funny and fun.
• Tchia. It’s like Breath of the Wild if Hyrule was a real place and the game devs wanted you to love it as much as they do. Fun and charming in a big way.
• Season. Hard to describe and I haven’t finished it yet, but the opening stuck with me. It’s about what we remember and what we choose to forget.
• Hollow Knight. Does Dark Souls arguably better than Dark Souls. I was put off by the Dark Soulsness and the aesthetic, but once I got a few hours in I was fully hooked. Another perfect game.
• Deep Rock Galactic. Great fun mining valuables and fighting alien bugs with friends.
• 13 Sentinels: Aegis Rim. A time-traveling anime story game with mecha combat.
• The Forgotten City. A time loop game where you are sent back to ancient Roman time.
• Nonary Games / Danganronpa. Both series are anime-inspired mystery games. If you want something that tries to be more cerebral and serious, Nonary is your ticket. If you want tongue-in-cheek violence, Danganronpa is the way to go.
• The Witness. A masterpiece puzzle game built on an incredibly simple core design. One of my favorite all time “a ha” moments came from this game.
• Citizen Sleeper. You are a synthetic being trying to survive on a space station and evade the megacorp that “owns” you. Your body is breaking down and you don’t know anyone, so you have to take it one day at a time and do what you can to survive. Clever mechanics and a really well told narrative.

That ended up being a lot more than I intended to share, but if this convinces anyone to give any of these games a shot, I think they’re in for a treat.

noita PC - a rougelike witch Sim full of secrets.

Dead Cells everything - Flawless metriodvania rougelite

The Forgotten City PC, PS, XB - A short time loop game that is just fantastic. I think it started as a skyrim mod

Dredge is pretty recent but it definitely impressed me with how it conveyed fear/paranoia in an eldritch horror setting. The fishing was also pretty fun!

The Long Drive is a cursed game that is surprisingly addicting.
Noita is a very difficult roguelike where “losing is fun” except that it’s not always, but many deaths are a learning opportunity. Each playthrough is different, but the map gen is ‘basically’ the same each game. It’s definitely worth your time.

The Messenger. Easily my favorite 2D platformer. It starts as a more modern and polished take on the original Ninja Gaiden games for NES, but it becomes so much more.

Inscryption. A rogue-like deckbuilder. You’d think that would make it similar to Slay the Spyre. But again, it becomes so much more.

I recommend both games any chance I have. They are very different, but both are better expecienced blind.

Brotato is a fun, mindless game if you like bullet hell games. Omori is a funny, wacky rpg with some horror elements. Good story to boot as well!

Diaries of a Spaceport Janitor is one of my favorite indie games of all time. The city design really captures the feeling of wandering around an unfamiliar, large, bustling place. The diary mechanic at the end of the day is a great way to get in character, and I like that you can decorate the apartment. I did some light data-mining (mostly item info and dialogue strings), and I even have fridge magnets of some of the pixel art!

Depanneur Nocturne is also a great evening’s worth of exploration and vibes, but I mention it because it has a reference to Spaceport Janitor and it made me SO happy when I realized that. :)

I don’t know what’s considered a “hidden gem” so I’m just going to shout out all the indie games that I think are at least 8/10 and recommend:

Rimworld Dead Cells Dredge Inscryption 7 Days to Die Mount and Blade: Warband Factorio Mordhau FTL: Faster than Light Raft Gunfire Reborn Into the Breach Hollow Knight Dome Keeper DUSK Golden Light Vampire Survivors Void Bastards

These are all fast, violent and kind of similar to each other:

• Broforce is a platformer with fully destructible levels where you save the world from Satan’s terrorist army. It has more explosions than a Michael Bay movie.
• Hotline Miami and its sequel are tactical top down games about shooting up houses. You die a lot but restarts are automatic so it’s no big deal.
• Katana Zero is like Hotline Miami if it was a platformer. You’re a cyber ninja who can slow down time and reflect bullets with his katana. The story is interesting and very emotional.
• Ghostrunner is Katana Zero but 3D.

Noita. It’s just so good. Easily in my top 5 games of all time.

Distance is an arcade racing game with a neon cyberpunk aesthetic. And the main campaign has elements of horror.

It’s one of the most unique games I’ve played - it’s almost more of a platformer than a racing game. And the main campaign is worth the asking price alone, but there’s 2 other campaigns, a bunch of standalone maps, a level editor with workshop support, a random track generator and multiplayer. Even as someone who really doesn’t care for racing games, I absolutely adore this game, and it’s criminally underrated.

Cataclysm: Dark Days Ahead isn’t really indie, it is straight up Open Source and a freaking good roguelike. The DDA variant focus heavily on the realism aspect of survival, but there are forks that try to gamefy it more.

There is also Rain World, which I am addicted for 3+ months now. It is also on sale, but before you buy it, know that you are going to die A LOT, but it really isn’t a big issue; it’s actually funny most times lol. Great lore too.

And one that I’ve rooted for a long time and I think flopped hard in its release is Below, but I very much still love it.

Also, one that I played for a bit last week and the soundtrack slaps hard is APE OUT.

How did I forget about Noita? This one is a masterpiece. Crafting a wand just to fucking obliterate yourself out of existence .3 seconds later is just chef’s kiss. Also hämis.

Not sure if it counts as a hidden gem, but the last indie game that I played through and really enjoyed was Wandersong, a musical platformer where you interact with everything through song. The same dev also put out Chicory, which is like a playable coloring book, but I haven’t had a chance to play that one yet.