i usually enjoy having to figure things out in games. i really liked portal and portal 2, i still haven't finished half-life but i do enjoy the the run, think, shoot, live philosophy of the game, but I always look things up whenever I play an open world game because I don't want to have to bother with having to figure out how to progress, or even if i do bother trying to figure out on my own, the clues i find will be cryptic and I'll just look up a walkthrough or something of the like. this is most prevalent in elden ring, and I especially don't like how there isn't a quest tracker. I believe that requiring a player to take notes to remember what they need to do on a quest is bad game design, even just letting the player look through past dialog would be extremely helpful. i get that there's a certain appeal to that, but I don't get it at all.
anyways, the point is to say that I enjoy puzzles and figuring things out, but I don't like it when things are so cryptic to the point where I have to look up how to do something because never in a million years would I be able to figure it out, and if i do somehow, I'll have absolutely no idea why it works and wonder how on earth I was supposed to figure it out in the first place. would someone with a mindset like mine enjoy tunic? I haven't looked a single thing up about it since all i've heard about it was to not look things up about it.
It sure sounds like you would like it. I will say that for me, everything about the game is fantastic, except for the combat, which is kinda terrible. Especially the boss fights. Feels to me like they're trying to mimic a souls-like style, but really really overshot on difficulty.
Basically, I say go for it, but don't hesitate to drop the difficulty settings, if you're like me.
Also, get yourself a physical notepad. Yeah, I kind of agree that if note-taking and such is intended as part of the game, there should be a venue to support that in-game, but there isn't really.
Also, also, don't feel bad about having to look up some stuff for the really late/post-game puzzles. One thing they toom WELL from Dark Souls is the idea of puzzles that are really made to be solved by the collective wisdom of the community, not just you.
Also, also, also, don't disregard the language puzzle, completely. I did, and when I looked it up later, I wish I hadn't I wish I'd at least have given it a shot, for myself.
Good luck!
Question about the language, is a full on conlang or is it just a cipher for English? I haven't been able to find any information on it.