Thank you for the review! You're not missing anything. The play balance needed more time, the game was too easy until the Necromancer, and the "Gameover: You Win!" screen didn't make it in. Honestly I didn't actually cut it, I just failed to write it down on my final "TODO" list and kind of forgot. Like, I checked off the "Game over" screen and failed to realize there are 2 forms of it and I actually only implemented one of them. Oh well!
So yeah, you killed the Necromancer, you won!