Hi Huitzilopochtli!
Thank you for your very in-depth and insightful comments! I always appreciate when someone takes the time to share their experience and thoughts on the game.
While I don’t want to say too much (because I don’t want to dilute your thoughts!), I’ll just clarify Challenge mode unlocks when you complete new game +, not new game. I hope you get a chance to experience all of new game +!
I’m very impressed you attempted the descent on new game, it’s definitely designed to be attempted after the player finishes the new game + story, though we decided to let new game players attempt it as well because we knew not everyone had completed new game + by the time we released the expansion. In hindsight maybe I would have locked it away until then, but either way I hope you ultimately enjoy your experience.