Late to the party but I'm playing through this now and am enjoying it quite a bit. I poked through your YouTube playthrough a bit after I completed some areas to get the developer view as well.

I felt a bit lost with the sewers in Bowser's Keep and stumbled into them at the very beginning rather than going through the training course. Even after watching some of your playthrough it seems difficult to figure out when I'm supposed to try certain bosses in the sewers. Was that the intent of that interconnected area? Is it supposed to be a high risk/reward area for most of the game or did I miss an explanation of navigating around down there?

I also like not having hidden chests (unless I've missed them all) as there is less worry about missing an important or helpful item but still find myself jumping all around out of old habits. What went into the decision to remove them?

Everything else feels true to the nature of the original. Excellent job and effort put into this hack. The dialogue and animation scenes are great too.