Level 4-1 (Mario vs. Donkey Kong)
The first area begins with the player directly underneath the platform with the Key. To reach it, the player has to press the yellow Color Switch while avoiding the Thwomp above. While carrying the Key, the player needs to alternate between the red and yellow Color Switches until the Thwomp on the right is stuck under the yellow platform. The player can then use the Springboard on the right to reach the upper platforms and progress to the locked door.
In the second area, the player needs to move right while avoiding a Thwomp. Above the spikes are two Falling Spikes, which will fall when the player gets near and turn into platforms for a short time when they stick into the ground. Using these new platforms, the player can reach a group of conveyor belts (as well as a 1-Up Mushroom and a Present) that lead to a platform with a Thwimp jumping over a blue Color Switch. To the left is the Thwomp from before, with a red Color Switch behind it. With the red Color Switch active and the Thwomp below the red platform, the player can climb a ladder to reach the Mini-Mario.