The art/layout/design in this is siiiccccck! It looks super easy to run. I do wonder what stopping the PCs from just walking down the spiral stair and skipping a large portion of the adventure?
Oh man, I really do love a manticore though! You've been really efficient with your space too. Having a large monster (manticore), bandits, and undead all in one adventure is super refreshing, and it would make for a really dynamic night of gameplay.