I'm still perplexed what the "secret" is on level 1 of PAM's The Dream. For fun, I thought I'd see what happens when you poke some of the screen memory with the debugger.
So if I write a bunch of FFs in, I can make horizontal platforms. I'm only putting them in one screen of the double buffer so it flickers and you'll "drop" when it disappears temporarily.
However, it's enough that you'll catch a line while you're falling and you can springboard off of them.
Screen memory for level 1 starts at 1000, around 1870 is into the banner.
What's actually kind of cool is that poking into the screen memory will affect the path of the billiard balls too.
This also explains why your character drops down when you are standing on the platform and the Eggle moves underneath you, it's changing the screen colors from the color of the platform to another "non-platform" color. This is also why you can "walk" or "jump" on top of the eggle as it has platform colors as part of it.
So after moving all over the screen, I don't think it's tied to your character being on any screen location.