Originally posted by TLMBIf you looked closely, their is a cement wall with
a turn block at the bottom...
What's to stop you from just carrying a shell, a Goomba, or even the P-Switch to throw at the turn block? Or using a cape to either whack it or just fly over? If you're going to get a Super Shell to follow you through an entire level, there needs to be some kind of pay-off at the end. (See the level "Shining Twilight" in Joshua's Treasure Hunt for an example)
Since you don't appear to be using Rexes, you could easily make an ExGfx file with Ninjis. Just paste their graphics in the proper place over the top of Rex. Magikoopa's going to conflict with Banzai Bill, if you plan to keep using it, so that's no good.
So yeah, no screenshots, link to an unfinished youtube level... I guess I'd better close this. This isn't a horrible start to your level, but it needs a lot more polishing.