Tip: Switch palace switches normally disappear if you replay the level. However, if you insert them as direct Map16 and use the hex-edit at $00EEB2 in the ROM map, you can replay the level without a problem.
Unlike the outdated BlockTool version by Jhonwilson, this one has an improvement:
-can modify the "speed limit" on how slow mairo is allowed rather than a speed of $00.
-can disable jumping while standing on top
-stick to the bottom and can move along with it (by pressing left or right) perfect for platforming levels that lacks a floor, doesn't work if yoshi or if mario is in water.
-and a walljump version