• 1 - The Ladder Glitch

At the beggining, go to the very first usable ladder. Don't go up. Press Down on the control pad when standing slighly left of centre of the ladder. It's at a very precise pixel so it's hard to do, especially while Jumpman is running. It requires practice. When I'm running to the right starting the stage, I press Down using the rhythm of game music as a landmark.

• 2 - Rivets

At stage 3, you normally remove the rivets by walking over them. But it's possible to press quickly forward then backward to touch them. The timing is extremely precise. If you do it too fast, you don't touch the rivet. And if you do it too slow, you fall. I think it's good to do this at the floor below DK's floor instead of going backwards by jumping.

• 3 - Edges

If you hit the edge of a platform correctly, you're somehow immediatly teleported on it, so it's a way to save some time.