In regards to the looping, I don't think it's used. On a related note, I've been working on implimenting the changes frantik has made to the ROM into doppleganger's source code and I've discovered that the pipe patch he used stomps all over the looping code.
I've integrated the following changes so far:
- Demo mode changes.
- End of game message related changes.
- Background color changes.
- Water pallet changes.
- Scenery changes.
- Terrain rendering bits.
- Bridge height adjustment.
- Level changes.
- Any changes in CHR-ROM.
There are still a handful of changes that I haven't implimented. I belive they're all related to the pipe hacking patch or frantik's prirana plant changes. I'd say I'm about a third to halfway done integrating the hacks into the ASM source.
The changes to the demo mode, scenery, levels, and CHR-ROM where all implimented by binary copy from the ROM produced by the latest patch. All the other changes have been implimented by changing the source code.
Once I've finished integrating the existing hacks, I'll start working on getting both sets of levels into one ROM. However, I will be out of town for the remainder of the week, so I proably won't get that done until next weekend, at the earliest.
In regards to the mysteriously appearing platform in that one level (I can't remember which one), I know what causes it. The game can only handle three elevators/platforms at once, if there are more than three active, the later ones are ignored. So the appearing platform isn't really a bug or a feature, it's a misfeature. Whether the engine limitation was intentionally abused by the level designer, I can't say, but I rather doubt it. (I discovered this a while back, but I didn't put two and two together until recently.)