I beat it with an A rank, though it took quite a few restarts to get it.. I suppose I should shoot for 0 lives, but getting that mid-height, far-length jump when you're coming off of a slope is really difficult.

It's interesting, sometimes activating a key will help a little, but sometimes not. I did find it quite irritating that getting the first red key would essentially kill all chances of getting the acorn.
The only thing I can really recommend is to put more random keys down BELOW, so that you can still push a troublesome platform back in position, but only at the cost of a life. Specifically, make sure the number of red keys is even, to avoid having that platform locked into a position that makes the game unplayable.
I know it sounds a bit hypocritical considering the levels I've made, but the ability to create an unbeatable scenario in this game is a major turnoff; Structurally it's very simple, even though it's quite difficult to navigate successfully, but because of that simple structure, I was left feeling like I was constantly repeating a single task. This heightened the frustration of finding out the level had fallen into an unbeatable scenario.

Hope that helps.

Seppukuties is like LBP Lite, on crack. Play it already!

Currently wrapped up in: Half Life, Portal, and User Created Source Mods
Games I want: (Wii)Mario Kart, Okami, Bully, Conduit,  No More Heroes 2 (GC) Eternal Darkness, Killer7, (PS2) Ico, God of War1&2, Legacy of Kain: SR2&Defiance

My Prediction: Wii will be achieve 48% market share by the end of 2008, and will achieve 50% by the end of june of 09. Prediction Failed.

<- Click to see more of her