Needs a Luigi block to go with the Mario block at the start
Are you supposed to be able to go through the purple pipe right after the midpoint? I thought that would only be a return pipe. It seems to make it a lot easier to get to the Red Star if you can take that pipe right from the start.
IF you want to leave that purple pipe open, then you need to move the sign in the Jacuzzi room back from the edge of the water as it's hard to exit on that side.
Feels kind of like a missed opportunity to not have something zany happen in the goal area. It would be awesome if you could make the castle itself chase Mario :D