Had to update the license.txt, didn't know it would produce a notification for that.
Hang in there, it's still on my mind and with my day job last year I didn't have the time to figure out a way to do this update properly and efficiently, and focused on new art instead. There's 84 possible zombies, so it's not trivial! I might be able to find a way to automate it. Possibly in time for a Halloween update?