At the last area of chapter 3, when you lose the dash ability, climb up the wall and then go LEFT. Then, go to the area in this picture:

As the arrows say, wall-jump on the wall to collect the dash fruit, but then quickly move right and fall down. If you do it right you can touch the fruit without falling to the spikes. After that, you can use this dash to move through the final barrier, and finish the game right away.

This shortcut is allowed only in the Any% category.