Tip: Layer 3 backgrounds and tides disappear when you hit a message box, so plan your level around that. For example, you can add a sublevel without layer 3 at the start/midpoint, and include your message there.
This platform sinks when Mario is touching it from above and rises when it is not. The first extra byte customises its sinking speed; the second one, its rising speed (vanilla values: 08FE). Please note that very high speeds can make the scale tiles not appear.
Completely coded from scratch (and thus, contains nothing of the somewhat obscure code of the dissasembly). It also fixes several bugs related to the platforms, such as the tile generation that occurs while in equilibrium and the cutoff that appears when despawning in a position of non-equilibrium.