The music and art is charming. Once you've implemented the feedback I'm reading here, I'd be keen to come back and play it more. As it stands there's a few undocumented features that Deeperbeige brought up, so I ended up just brute forcing the answer.
Perhaps fill out just one space, to give people a head start, and possibility to figure it out from fewer guesses. Also, the fact that a token can be in the right place, but also considered adjacent by another token is confusing. E.g. guessing two ravens next to each other, only one of them actually exists - the other one says that it's adjacent, which confuses me and makes me waste a guess, when really the 'adjacent' token is the one I correctly guessed. (It especially makes omens where "pieces must be adjacent" difficult to use as hints)
I love Mastermind, and I could love this too. I'm staying tuned to this game's updates :)