I just seen (and played) SirCamaris redesigned level No.1 and I must say that's exactly what I had in mind when it comes to redesigning
He preserved the gameplay(changed it a bit without damaging the main concept), preserved the level-frame size, preserved camera position and created the new level geometry solution, which is also the focus of his design.
I have only one concern regarding his gameplay modification, since it haven't yet been decided if we are to go with 3D or 2D characters(and level-depth could potentially be the problem when it comes to 2D animated characters), but that's something that we are all to discuss later on...