My Top 10 are:
1. Celeste: Probably the greatest 2D platformer ever made, it has ton of great unique mechanics, incredible music, instant screen respawn system and its theme of dealing with Anxiety/Depression are well done imo. Only wish the Collectables had better rewards. (Ashamed I havent went back yet for some of the secret harder levels).
2. Disco Elysium: It was a tossup between this and Celeste, I chose Celeste because that game didnt have bugs that wasted 3 hours of gameplay. Anywho its an incredible CRPG Adventure game that has such an interesting personality based level system I've never seen before, so many interesting unique interactions can occur based on what personality you decide for your character, the world is interesting and the game is not afraid to go places and god damn is it hilarious. Some incredible characters and magical moments in this one.
3. Inscryption: I love Card Games and although there are going to be technically better gameplay wise card games on this list this one has the most soul. The music is incredible, the characters are interesting, the visual flair is very atmospheric, it has a variety of takes on its Card game system very unique. It's designed to be a power fantasy and it has some rougelike dlc that alot of fun.
4. Monster Train: Like I said I love Card Games, gameplay wise this one is king in the indie realm, the variety is super fun with its various build leaders and secondaries (and its a Rouglike) and no run feels like you were cheated but with the shards it can become an incredibly challenging puzzle. Blew through almost 200 hours on this last year, dangerous stuff.
5. Undertale: A very unique RPG with creative smup mechanics and character interactions. The world has a ton of charm and heart and the music is yet again incredible. The Genocide run of this game may have had me fight the hardest boss Ive ever fought in a video game and some of the stuff you get to do in that run is amazingly evil haha. It has some cringe in it but its undeniably great.
6. Bug Fables: I love Paper Mario, this is a Paper Mario clone (Nintendo wont do it so someone had to) with its own take on parts of the battle system (sometimes one upping PM) and the partner system. The world and characters are charming, the music is good, the side content was fun (especially what they use Tattling on enemies for), I smiled my whole playthrough.
7. Slay the Spire: Did you know I love Card Game's? Yeah this is the OG Roguelike Card Game, its gameplay is great even if its art and music are mid as fuck. Also it sometimes will fuck over your run just because it feels like it and runs last a long time I should know Ive put like 150 plus hours into it like Monster Train like a psycho, super addictive.
8. Psuedoregalia: I also love 3d plaformers, this is a 4 hour one is kinda like a beta for an incredible 3d platformer but I cant deny in that 4 hours it really impressed me gameplay wise. Your moveset is pretty incredible, it feels really good, it has the BEST Wall kick in video games which is impressive considering Mario is AAA. It trusts its player to know how to play video games and thats appreciated, it also has an incredibly chill vibe with some great music. Its downsides are mostly its length, a lack of personality in the world and no map since it is a metroidvania as well (this doesnt matter as much because its small but still), I cant wait to see what this team does next.
9. Hades: A really fun Action Roguelike with great Dialogue and interesting characters, tons of stuff to level up and unlock too, just a really fun time that you can turn your brain off to play, the weapons have plenty of variety as well as how you form your builds (not on Isaacs level but still). Only thing that keeps me from loving it more is the Isometric view isnt my favorite in video games (Disco isnt really gameplay oriented so it doesnt matter there).
10. What Remains of Edith Finch: An incredibly interesting interactive Walking sim/Narrative game with light gameplay elements about mysterious deaths in this family is so fascinating, its an incredibly interesting story Id recommend to all, might be my favorite pure narrative game.
Honorable Mentions:
The Binding of Isaac: The OG Roguelike and arguable the best at that part of it in the genre, just a OG Zelda Dungeon Crawler/Run and Gun Smup game with a ton of build variety and unlockables, definitely a classic, tons of hours spent here.
A Hat in Time: Love 3d Platformers and the game has a ton of charm. Its really fun to play too (after you fix the camera mode, cant believe its not default), some things are a bit derivative but it controls well and has you go to interesting places and has plenty of fun platforming challenges, really love the Snatcher character as well.
Braid: This puzzle platformer has some of the greatest puzzle designs of all time, its music is incredibly calming and it has a great artstyle, I just wish there was more of it, its pretty short but its very good, if I was more of a puzzle's are king guy then this should have been in my top 10 unquestionably. Story is pretentious as hell tho and kinda non existent.
The Case of the Golden Idol: This is the first true detective game Ive ever played, it has a cool lovecraftian vibe with great music and interesting scenarios/logic puzzles, its so good at setting up red hairings while also having the truth make sense as well, the characters you discover are pretty interesting as well, cant wait for its sequel.
Spiritfarer: This is a interesting one since its Gameplay isnt really what makes it special, its kind of 2d Adventure/Build game with platforming. This game is about helping people in the world of the dead move on to whatever is next its incredibly powerful emotionally and very sad/heartwarming. It's a more relaxing type of game where you build your ship to carry more souls aboard it and do missions for your guests, if you are looking to feel something I definitely recommend it.
There are alot more great indies Ive played but I gotta keep it reasonable and these are the fav's.