The Whoa Zone is the fourth and final area in the chapter Outer Space in Super Paper Mario. It's a giant maze that consists of flipping to 3D and 2D and gravity flips. The final boss of this area is Mr. L and the Brobot.
After floating and walking through space and planets, Mario and his friends follow Squig to the Whoa Zone, a gigantic space maze. Mario must traverse through a maze where he has to step on platform to make the gravity change, so he can walk on the walls and ceiling. When you reach the end, a man jumps out into the screen. He calls himself "Mr. L." After defeating him, he calls over a robot that looks like his face. It's called the Brobot. Squig then turns his body into a shooter that shoots laser balls. Mr. L and the Brobot then break the screen, and Mario is sent back to space. This also changes the boss battle into a scrolling shooter. After beating him and the Brobot, the screen turns back to the Whoa Zone, but is in an inaccessible place, showing an alien that looks like Squig. That's when Squig finds out that he is a prince, born to help the chosen one. After finding out, he gives Mario the fifth Pure Heart.