Hi - thank you so much for playing and thank you for your comments. All your points about the game are well made, especially the very clear need for a tutorial. I was surprised after I got the basic mechanics programmed how many tricky decisions there were to make about visibility, given that there isn't really a traditional "line of sight" with the structure of the maps.Your suggestion about Wraiths is a good addition to that.
Monster generation is randomized per level according to static probabilities, plus new monsters spawn after a threshold of turns, which gets shorter and shorter.
And your screenshot is so painful to look at! I knew that the level generation algorithm was too loose, but thought that the tile swapping ability sort of "covers" for the majority of bad spawns...but that combination of tiles, blanks, and fire you got below is really punishing.
Oh! And double walls on tiles just signify "you've been here before" it's to help you figure out which paths you haven't taken if you're stuck navigating a tough level.