Really enjoyed this one! Although I don't have a printer so it took me almost as long to figure out how to play it digitally as it did to clear all the levels ha ha.
Not sure if this is intended or not but the rules as written don't forbid the player from shooting a guard with a crossbow through a wall. Thematically it doesn't make sense to me that the crossbow bolt can go through walls. But you did specify that the distraction stone can't be thrown through a wall, which signals to me that if the crossbow wasn't meant to work this way then you would have clarified it in the rules.