I figured a video might be a good way for you to tell what points I struggled with, as well as a good way to point out things that are good/may need tweaking as I come across them. So here's my initial impressions:
Really nice level overall. Very exhilerating.
I talk a lot about an error pertaining to getting hit while travelling through a barrel. It seems that's a bug in SMBX2. Hopefully we can fix it in the next patch.