Stage 4-3 of Super Mario Bros. 2 is a kind of long one. You have to go across an impossible-to-jump-over gap, then climb up one tower and down another before fighting the boss of the area.

But you can skip most of that.

First, choose the Princess.

Ride the Birdo Egg across the gap as normal

Then, instead of going through the door, make a flying leap toward the right.

Once you land, go in the second door on that platform

To skip right to the boss's chamber!

This cuts the stage down to just a couple of minutes... unless you go in that door that I told you to not go in. That one is locked on the other side, which will require you to scale the tower, grab a key, and then go back down, which totally negates taking this shortcut in the first place.