Thanks for checking out our game and sorry you got stuck! Did you try pressing Z to interact with signs and the ghost? If you decide to give it another shot, try reading the backs of signs too :)
Ah! Right, that was MUCH too obscure :). But knowing that each side of the sign is separately interactable, and some sides do nothing, others work, was a big help. I think at minimum you need to highlight the sign with an outline color to show it will be interacted (or not) and probably use a different color for different sides (top vs bottom) to hint that its worth doing both.
Really liked discovering and using the song - would love to have more songs to learn and use.
Snakes were bugged - 9 in 10 never moved so just walked to them and spammed LMB.