Yeah, I got into Twine as a graphics-lite platform to learn about the logic of game design. It allows me to use text to do a lot, and now that I'm working on digital boardgames I can work with static "cards" like the enemies here. I did do stuff with GameMaker when it was free (so imagine how long ago it was, GM 2 wasn't even out) but having to make the interface itself was a lot of work.
Glad the theme came through! I'm no artist (as if you couldn't tell :P), and adding sound is still too new for me, so building atmosphere is an uphill battle. The idea of a necromancer was there from the start, before I even knew why you'd need blood or bones.