Beautiful game. First played it at 2 am and found it very difficult. Replayed it at 7pm and found it brillant. Very smart choices of monsters.
The inversion/deconstruction of minesweeper as "mines change number around them" instead of "numbers indicate how much mines are around" is also a very fun notion to play with.
Have you forced every board to be solvable without random guess? It feels like you did, but it also seems difficult algorithmically ...