Level E2-1 is the ninth course of Orbiting Observatory in Mario vs. Donkey Kong: Tipping Stars. It is the first in a series of levels in Orbiting Observatory to lack the Magnet mechanic, focusing instead on other mechanics from the game.
The level features three Mini Marios.
The course contains Red Girder Rivets and Pipes placed at different heights, as well as many platforms and walls of Color Blocks that can be toggled by pressing Color Switches. Multiple Girder Pickups are scattered throughout the course, increasing the number of Red Girders in the stockpile upon collection. The player can initially progress with only the Mini Mario on the bottom floor, which has to help the other two Minis escape from their traps. One of these Mini Marios is blocked behind a wall of Blue Color Blocks at the left, while the other Mini Mario faces a wall of spikes at the top of the course; in both situations, a corresponding Color Switch has to be sought and pressed in order to set the Minis free.
The free Mini Mario should first be guided with a bridge of Red Girders into the blue Pipe that leads higher up. Exiting the Pipe, the Mini goes left and immediately encounters a Blue Color Switch, freeing the other Mini Mario below him. Both Mini Marios should then return to the bottom via a Red Girder slope and re-enter the blue Pipe from below. This time, upon exiting it, they go right to encounter a line of Split Pipes in the wall ahead of them. With a Red Girder, the player can help the Minis reach a path of Yellow Color Blocks underneath, which leads them into a yellow Split Pipe. Coming out of the other side, the Minis reach a Red Color Switch, which deactivates the path of Red Color Blocks in front of the third Mini Mario. This enables the toy to escape the area it is in without touching the spikes ahead. At the left, there is a Yellow Color Switch that should be pressed to disable the row of Yellow Color Blocks from earlier. When all Minis are assembled, the player should draw a slope of Red Girders that leads to the bottom right corner, having disabled the Yellow Color Blocks that obstructed the way down. A wall of Rocks blocks the Goal Door there; sliding downward, the Minis break the wall of Rocks and enter the door, clearing the level.
The M Coin is located at the same level as the top red Split Pipe. The Minis should navigate the red pair of Split Pipes and, with the help of a Red Girder, reach and collect the coin.
The following data applies in both the Nintendo 3DS and the Wii U versions of the game.