Level 2-4 (Mario vs. Donkey Kong)
The first area has a Nitpicker flying above that the player needs to avoid while clearing the area. The player starts next to the locked door and a ladder, above which is the Key. The player needs to throw the Key onto the colored platform and press the Color Switches to the right to make the Key fall to the ground below, then quickly use the Springboard on the left to get back onto the platform and climb down the ladder to grab the Key before its timer runs out. The player is now able to unlock the door.
The second area has two moving platforms and several chambers that can be accessed depending on what Color Switch is active. In order to reach the Mini-Mario, the player needs to press the blue Color Switch second-from-the-top chamber on the right. The yellow Color Switch in the chamber directly across from the Mini-Mario then needs to be pressed in order to access the chamber with the Mini-Mario.