Mushroom Heights

Mushroom Heights, or Acorn Plains-4, is the fourth level of Acorn Plains in New Super Mario Bros. U. It is the first athletic course, and the first course to introduce Goombrats and Balloon Baby Yoshi (although the same Baby Yoshi can be acquired just before Mushroom Heights on the world map). This is the first course of the Acrobat Pack in Boost Rush. This course is unlocked by completing Yoshi Hill, and this course in turn unlocks Lemmy's Swingback Castle upon completion.

Layout
The course mainly comprises of moving mushrooms, such as ones that move up and down, or ones that tilt forward and backward. The enemies are mostly Piranha Plants, including the pipe and big variety, though the course does introduce a new type of Goomba, the Goombrat, Goombas with stems on the top of their head. They act like red Koopa Troopas, as they turn around on the edge of ledges.

Star Coins

 * Star Coin 1: On a blue mushroom platform near the beginning of the course, the player must use the Flying Squirrel Suit or Balloon Baby Yoshi to reach it. Alternatively, the player can make a running jump from the stage's first set of Blocks to reach it.
 * Star Coin 2: Same as Star Coin 1, only that the Star Coin is below a blue mushroom platform.
 * Star Coin 3: Under a moving mushroom platform and between two Big Piranha Plants, the player must wait until one of the latter goes down, or gently glide their way down.

Enemies

 * Piranha Plants
 * Big Piranha Plants
 * Goombrats
 * Koopa Troopas