I did not get the final thank you screen, just the sound you get from pressing the "reset" button followed by a full reset. It happened right as I clicked the very last upgrade left on my tree (I don't remember which one, sorry).
For sacrifice efficiency, maybe add some kind of torture devices popping up? Like a guillotine, iron maiden, stuff like that. I think old Catholic torture devices would fit the vibe well. You could also just upgrade the death animation to be explosions to keep it simple. Even just adding static images to the church screen would give the player a better sense of progression I think.