How bypass hidden blocks with Yoshi. This trick have been in the game since day one. But still many people dosent know it. So duck and jump, when your head is little bit over where botton part of the hidden block is, hit Z.
Take some time to figure it out how to beat this. You have to use that p-switch to push you out off the screen to reach the goal in time. No wonder clear% was 0,02%