> Sennaar didn't gel with me, because language-based deduction imply an "arbitrariness" ("wobbliness"?) and mis-interpretations

After not too far in, you eventually start confirming the meanings of words. Eventually you confirm the meaning of every word of every language. So, while learning a language can be a challenge of interpretation, eventually you do get concrete meanings.

Edit: I'd also recommend The Sexy Brutale for your list, it's a time loop detective game.