Okay, got the basic framework for a level generator with an interactive editor implemented:

When you change the parameters the view updates immediately

Currently the generator just spawns a lot of colored boxes.  The next step is writing some more interesting generators, and setting up the physics so that you can jump from box to box.

Given the theme, a tile based platformer adapted to 3D might be an idea, I’ll see where I go from here (no, I don’t have any overall plan :p ).