Tip: After editing your overworld, make sure to use an EMPTY save file, as save files with progress may load Mario's position based on previous versions of the overworld. Note that altered level flags will also only take effect on new save files.
While this level had some potential, I feel like it's ruined by the sprites. Most of the NPCs feel like they were just randomly placed to add some difficulty to the level, and don't work well with the level's structure overall.
While it's not a bad level, it definitely needs some work on the NPC placement before being accepted.