Undead

Undead is a grid-based puzzle where the player must figure out which of the monsters (vampire, ghost or zombie) is in each empty grid square; only the total number of each type of monster is known to the player. Diagonal two-sided mirrors are located in certain squares. Numbers around the grid state how many monsters are visible to an observer looking straight into the grid from that point; zombies are visible normally in all circumstances, ghosts are not visible directly but can be seen if reflected in a mirror, and vampires are visible directly but not visible as mirror reflections.