Thanks! I spent so much time learning to make my own behaviors for the platforms and tops I didn't have time left for tutorial menus etc. Probably didn't have to spend all that time to make my own sound track with VCVrack either... :D
Three way collisions are a ridiculous challenge in GDevelop. I had to create a new behavior that draws collision boxes all over every object so I could detect where collisions were happening. That made things like "Top is on Platform and colliding Left Side with Platform" possible. otherwise there was no way to select platform is colliding with platform and stop motion in one direction but allow a second top to reverse direction. It ends up being this gross global structure that tracks collisions outside of normal collisions but it works so meh.