Really Rolling Hills

Really Rolling Hills, or World 2-4, is the tenth regular level of Super Mario 3D World and the fourth one in World 2. It is unlocked via completing Puffprod Peaks or Shadow-Play Alley, and its own completion unlocks Big Galoomba Blockade. The main gimmick of this level is the hills that constantly turn in circles.

Layout
The level starts in a grassy plain inhabited by Galoombas and Skipsqueaks, with a nearby ? Block giving the player a power-up. After passing some more enemies, rolling hills, and a Red Ring, the player reaches the Checkpoint Flag. A nearby pipe leads the player to an underground area infested with Galoombas, Spiny Skipsqueaks, and cog-like platforms. After navigating through the area, the player comes upon a pipe which leads them to the Goal Pole.

Green Stars

 * Green Star 1: Near the very beginning, the player must use the Cat form to climb a cliff between two clear pipes.
 * Green Star 2: During the underground portion of the level, there is a green Warp Pipe that's partially blocked by purple Brick Blocks. The pipe leads to an odd room with Color Panels that, when all activated, will reveal the second Green Star.
 * Green Star 3: After the second star, the player must fall between the rotating wheels to find the third Green Star.

Stamp

 * Near the beginning, there is a Character Switch that only Mario can activate. That switch reveals the stamp. The stamp is Small Mario.

Enemies

 * Skipsqueaks
 * Galoombas
 * Micro Goombas
 * Spiny Skipsqueaks
 * Goombas