Terraria
Saying that I spend most of my gaming time playing indie games would be somewhat misleading--not because I play many AAA games, but because over 50% of my time spent playing any game, at all, has been spent playing Terraria. I have over 2300 hours in it; At one point, over 2% of my total time spent awake had been spent playing Terraria.
I think it's a beautiful little game. It's like combining the do-what-you-want nature of Minecraft with the fine-tuned progression of a Metroidvania. You always have a variety of fun options at your disposal to progress, be that exploring new areas, finding a specific accessory, fishing for potion ingredients, building a better arena to fight a boss in, building up your home base, or just decorating what you've done already. This breadth of options also makes it a great multiplayer game, because you can be separate or together while still ultimately pursuing the same goals.
It's also a hopeful game to stay in the community for. As much as the developers want to have their final update, they never seem to hold that promise for long :P
Besides official updates, Terraria has a robust modding community, some of which add a phenomenal amount of content while keeping the core gameplay loops intact. Terraria's progression and style lend itself to additions, new pathways for progression, new bosses and items, new progression points to be reached after the game's normal final boss. The most popular Terraria mod, Calamity, easily doubles the amount of content in the game. (Though my favorite mod is Thorium).
Terraria also has a fantastic wiki at terraria.wiki.gg. It's a game that gets better when you know more about it, since that lets you make more informed decisions about progression paths to pursue. I recommend having the wiki open the whole time you play it. and do NOT use the Fandom wiki, which is evil.
While the game itself is very fun, a lot of my gameplay time has actually been spent in a specific Terraria minigame server, which sounds very sily (and it is) but was genuinely quite enjoyable.
OneShot
Play this game blind.
Celeste
Extremely solid precision platformer. It's very well designed to present you with a challenge to make you feel accomplished when you succeed without being demotivating when you fail. It's an incredibly fair game even as it gets progressively more difficult. The music is great, the story works off of the gameplay in a fantastic way, and it has content to last you a long time--including, on the pc version, mods (Spring Collab and Strawberry Jam Collab) to add much more.
It's also, like, the prototypical trans girl game, alongside Fallout: New Vegas. This was even true before its lead developer came out as trans.
If you want to feel evil or like a rulebreaker of some kind, it's a fun challenge to play this game two-player. As in, one player controls the movement while another player controls the jumping, dashing, and climbing. Do not do this with someone you dislike.
Hollow Knight
Beautiful game. Hollow Knight has all the good design choices of a metroidvania regarding its progression system, and it has solid combat, but what really sells it is the atmosphere of its world. It's one of those games where you won't mind letting the character sit still, listening to the music and absorbing the beautiful backgrounds. The lore, and the way it's told, is also wonderful.
In Stars and Time
This is the first piece of media with a time loop I've seen to genuinely explore the impact that it could have on someone. The theme it has around manipulating your friends, to your own downfall, also hit pretty close for me. It's a cute and melancholic RPGMaker game. It's also very gay in multiple respects.
More
Other games that I've enjoyed include A Short Hike, Bug Fables, Night in the Woods, the To The Moon trilogy, ESC, Enter the Gungeon, and of course Undertale. I hope to write about more sometime, but I'm becoming impatient to update my website :3
Yet More
A lot of the games on this page are quite old. I don't think the value of the experience of a game goes down much over time: Cave Story, for example, is just as good as it was in 2004. But there are still many great indie games that I've missed out on recently, like ULTRAKILL or Slay The Princess. And, of course, there are those games which I'm in the middle of, like Disco Elysium.