This is a pretty cool demo. I like the levels, but I think the first part of Puddle Fortress didn't really seem like a castle level to me. t was very cramped, and the really fast autoscroll plus the hordes of koopa troopas made it seem more of an athletic level. The second part of it was really cool though, The vertical part could have been longer though. The boss also didnt fit, it kind of surprised me. The Music choices were fantastic, and the levels were fun. Cant wait to see this as a full hack.
heres my gameplay of it: https://www.youtube.com/watch?v=-gaUtPbnPuU