Hi, thanks for playing! Glad you liked the game.
No expansion or follow-up is currently planned, but you never know. The game hasn't gotten much traction so it didn't seem like there was much interest in it.
As for the Wraith Wail, yeah, that's probably a bug! For now, just imagine a spooky wail and I'll see if I can get it fixed sometime this weekend. Thanks for taking the time to report it!