I had hard times trying to understand what to do at start. So on my first walkthrough I completed game by solving only final puzzle, because I could pick up the fourth piece without doing all other puzzles - probably bug. Also it's somewhat not clear in terms of game logic why Hovanets can't place boards without candle, or why you need exactly that candle etc.
Otherwise cool game, looking good too. Some sounds and ambient would totally add a lot to overall mood of the game.