I like the feeling of everything that you're doing. The design on Marie is very cool, and everything hangs together really well.
I dig the concept of the grotesques. I wish there was a given reason why they're aggressive toward the players. I know it's implied that they attack the Nazis too, but it feels like there's space for them to have been manipulated by the invaders, which might make the Notre Dame quest hang together better with the rest of the game.
Mechanically, I worry that the countdown clock is a little aggressive. It's good that they feel relentless, but I worry it will turn into an annoyance rather than feeling like a danger when they attack every 4 turns or you need to constantly feed successes into keeping them away.