New Super Mario Bros. U (WiiU)

Five bonus coins
If a multi-coin block is still active after you collect 10 coins from it, the final hit will release five coins.
Generous flowers
Ground-pound or spin near a dancing flower and one coin will pop out. You can do this once per flower.
Flagpole bonus

Grab a flagpole to stop the timer when the tens and ones digits match (and are not zero). The Super Mario Bros. course clear theme will play, fireworks will go off, and Toad will give you a power-up for your item inventory. The item you'll get depends on the number matched in the timer.

Remaining on timerItem
X11, X22, X33Super Mushroom
X44Fire Flower
X55Ice Flower
X66Mini Mushroom
X77Super Acorn
X88, X99Super Star
Save anytime
After clearing Peach's Castle, a "Save" option will replace "Quick Save" on the map screen menu.
Unlock Superstar Road
Clear Peach's Castle to open Superstar Road, the ninth world. In Superstar Road, each course is locked until you collect all the Star Coins in the corresponding world. For example, collecting all the Star Coins in Layer-Cake Desert (World 2) will open Superstar Road-2.
Unlock the Secret Island
Clearing Peach's Castle also opens the Secret Island. Inside the Secret Island's mushroom house you can view various records, such as number of coins collected, Goombas stomped, and goal poles reached.
Unlock Superstar Road-9
Superstar Road-9 will appear on the map screen after you've collected all the Star Coins in Superstar Road courses 1 through 8.
File stars

Here are the requirements to get stars to appear on your save file:

  • Star #1: Beat Bowser in Peach's Castle
  • Star #2: Clear all courses up through Peach's Castle
  • Star #3: Collect all the Star Coins up through Peach's Castle
  • Star #4: Unlock the final (ninth) course in Superstar Road
  • Star #5: Collect all the Star Coins in Superstar Road, find all standard and secret exits, and catch Nabbit in Worlds 1 through 7

When you have all five stars, all the Toad Houses will reappear, and you'll be able to re-enter them as many times as you wish.