New Super Mario Bros. (NDS)
The following courses contain secret exits:
Instead of taking the pipe to the normal exit, use the nearby tilting platform to get on top of the ceiling. Go to the right and you'll find a hidden area containing the third Star Coin and a pipe leading to the secret exit.
For this exit, you'll have to be Shell Mario (or have a Shell in reserve). First, take the door to the small room that contains a Star Coin and moving blocks. Next, carefully make your way to the gap in the blocks on the right side of the screen. Walk off-screen to the right, and you'll end up in another room that contains a red pipe blocked by bricks. Break the bricks with Mario's shell-dash attack and take the red pipe to the secret exit.
This secret exit opens up a Warp Cannon to World 5.
Near the beginning of the second area, hit the ?-Switch to raise the water, then swim up through the gap in the ceiling. You'll end up in a room with coins and another ?-Switch. Hit the switch while the first one is still active and the water will rise again, which will let you swim to the path in the upper-right. Take the path to find the secret exit.
Take the yellow pipe instead of the green pipe at the end of the first area to find a Star Coin and the path to the secret exit. To reach the yellow pipe, jump off the last spinning platform, float over to the red Koopa Troopa by the green pipe, then bounce off of him to the upper platform.
This secret exit opens up a Warp Cannon to World 5.
Bring along a Mini Mushroom for this exit. When you reach the water area, go left and enter the mini-pipe. It'll take you right to the secret exit.
Defeat the boss as Mini Mario. Instead of going to World 3, Mini Mario will drop into the mini-sized passage that leads to World 4.
After the midway point, you'll have to ride a moving mushroom platform that takes you under a set of red, yellow, and green pipes. Jump into the green pipe to find a coin room and the secret exit.
The ?-Switch in the brick block makes two doors appear: One above you, which leads to the standard exit, and one off-screen to the left, which leads to the secret exit. Once you hit the switch, move quickly back up the stairs and jump down the other staircase. The door will be right next to the ?-Switch under the staircase. If you don't make it in time, go back to the brick block switch and try again.
This secret exit opens up a Warp Cannon to World 6.
When you're riding the blue dinosaur, watch for the five-block-long platform that has a ?-Block on each end. Jump onto the platform, stand on the center brick block, and jump straight up to hit a hidden block containing a vine. Climb the vine to find a pipe that leads to the secret exit.
Grab a Mini Mushroom before entering this course. After hitting a !-Switch to reach a door, you'll be in a room with a !-Switch and a pipe. As Mini Mario, get on top of the pipe, then wall jump from the pipe to the platform on the other side. Wall jump up a bit further to find a door that takes you to the secret exit.
This secret exit opens up a Warp Cannon to World 7.
About halfway between the midway point and the goal, there's an upside-down green pipe near a large group of brick blocks. The pipe leads to the secret exit, but beware of the two Spike Tops and Piranha Plant when you're on the icy platform.
Grab a shell power-up before entering this course. Between the third Star Coin and the standard exit, there's a spot where you can wall jump up through an opening in the icy ceiling. Jump on top of the ceiling on the left, then use Mario's shell-dash attack to clear a path to the green pipe. Enter the pipe to find the secret exit.
Keep ascending the staircases until you reach the row of three brick blocks next to the left wall. Each brick has an invisible coin block above it, so jump up to reveal the blocks. From the now-visible block in the middle, jump (if you're small Mario) or duck and jump (if you're a Super-sized Mario) straight up to reveal an invisible vine block. Climb the vine, but stay on it while the Broozer bashes through the wall that is blocking a door. Enter the door, survive the haunted elevator area, and the secret exit is yours.
This secret exit opens up a Warp Cannon to World 8.
Defeat the boss as Mini Mario. Instead of going to World 6, Mini Mario will drop into the mini-sized passage that leads to World 7.
In the first room, hit the ?-Switch (located in the first brick block) and take the door on the lower-right. This will take you to a room with a moving, invisible block that contains another ?-Switch. Luckily, the hands in the room point to the block's location. Hit the block, hit the switch, then go to the right and use the temporary platforms to reach the door above. Now you'll be in a room with a P-Switch and coins all around. Hit the P-Switch and run left. As you're running, look for a shining brick block above youit contains a vine. Quickly hit the block and climb the vine to the door that leads to the secret exit.
It's Mini Mario time! Stay on the left side as you go up and you'll see a flying ?-Block shortly after you pass the midway point and Red-Coin Ring. From the flying ?-Block, jump into the gap in the wall, then curve a jump up and back to the left to land on the platform above you. Drop down and take the mini-pipe to the secret exit.
Near the end, there's a green pipe in the ground covered by blocks. You can use Bob-ombs (challenging) or a Mega Mushroom (easier) to clear a way to the pipe, which leads to a coin room and the secret exit.
Right after the midway point you'll see two rows of blocks. The center block in the bottom row contains a vine, but you'll have to break the center block in the top row first so that the vine can grow all the way up. Climb the vine to the next area, ride the moving mushroom platform to the green pipe, then jump inside to find the secret exit.