I just finished a first pass at blocking it out. Hopefully I have most of the timing and physics worked out such that it just becomes a nice, easy process of refining(ha!). Let me know what you think. Input now is much easier to implement than down the spline.
My apologies, youtube really chewed up the beginning of it with compression, but it's just a hold on the environment for a beat before the first monster falls into frame, so you're not missing much.