Man, I am stumped on getting to Mt. Sus.  I finally found the invisible blocks in the sky (2.1). after trying to double-jump off the bear in 3.1 to reach 3.2 and, alternately, trying to triple jump without success in the small chute under the clouds in 2.7 in for several hours.  The blocks just lead back to the party house (2.2), though, and although we are on the previously-inaccessible roof there is nothing new to scan and we are prevented from jumping to what would presumably be 1.2 by something on the other side of the screen transition.  We also can't jump through the one-tile gap at the top-right of 2.1 to reach 1.1 :/  I've been trying to jump off the last invisible block in 2.1 so that I just barely clear the stairs down to 3.1 and then correct right to avoid landing on that little dirt lip at the top left in order to preserve bounce height so I could bounce all the way to the top left of the screen and land on that ledge, but 1) it's really hard, especially since the stuff you are jumping off of and around is invisible and 2) I *think* but cannot be sure because there are invisible blocks that there may actually be a max height that flowers launch you no matter how high you were beforehand and the whole plan is impossible.

Anyone know how to get up there?  I've got a lot of clouds left to scan ;)