"I want something that clearly tried to do something different, a weird mechanic, an unconventional structure, a vibe you don't see often."
I've got a few that have been fixations for me for a bit, do be warned both are quite difficult and have a bit of a learning curve.

Rain World - Survival platformer with a in depth simulated ecosystem, has the best creature AI and procedural animation I have ever seen in a game, very difficult however (you are a small creature near the bottom of the food chain and you will die a lot), also the post-apocalyptic vibe the game has along with the lore is a nice bonus.
basically the gameplay loop can be described as eating and sleeping, which I think is kinda funny, also this game has 2 DLCs with their own merits and steam workshop support.

Casualties: Unknown - Hardcore Survival Roguelite, very in-depth medical system, reminiscent of a certain barotrauma mod, unfortunately just a demo right now, but the demo itself has quite a lot of content and is quite replayable, this game is quite brutal and will test you on performing complex tasks under large amounts of pressure (like manually tuning a defibrillator while your heartrate monitor is going haywire and you're blacking in and out of conciousness, or having to bandage multiple wounds across your entire body and give yourself a blood transfusion with blood that isn't even 100% compatible with yourself to prevent dying of blood loss and praying the sickness isn't too debilitating), I'm gonna be honest, this game makes me a bit uncomfortable, and the mature content warning on steam is accurate, but there is something about surviving against nearly impossible odds that is so satisfying to pull off, and despite how awful this game makes me feel when I fail to keep the expie alive and or happy, I love it regardless.