New Super Mario Bros./World 3

World 3-1
Slide down the pipe to start the level. The first Star Coin is past the checkpoint. When you see a red pipe next to two green pipes, head down the middle pipe. Swim to the right, grab the Star Coin, and go out the pipe on the right. For the second Star Coin, wait until the big fish starts heading towards the right, and grab it. To make the third Star Coin easier to grab, hit the switch. If you don't, you can always destroy the blocks, but the fish might get you when you grab the coin. Swim as fast as you can and head up the pipe to finish the level.

World 3-A
Head right. Past the checkpoint, hit the red switch in the water to make blocks appear and continue. In the next water hole, go down and let the water-glider destroy blocks to access the first Star Coin. Get out of the water and head right. Run and jump from the first barrel to reach the second Star Coin. Go through the green warp pipe. If you are Mini Mario or have a Mini Mushroom go in the overhead green warp pipe and grab the third Star Coin by running over the water and jumping. Go out the green pipe on the right, and finish the level.

World 3-2
Head right, and when you hit the checkpoint, go down the yellow warp pipe. Grab the first Star Coin and head out the green warp pipe. Head across the balancing platforms and jump to the second Star Coin. If you head into the green pipe when you get on the moving mushroom, you can get a lot of coins and it leads to the alternate exit, which leads to World 3-B. Otherwise, keep heading right. Grab the third Star Coin when the mushroom is extremely tilted and finish the level.

World 3-Tower
Go down the middle pipe to be launched up. Grab the grid by pressing up. You can destroy things on the opposite side by pressing the Dash button or jump up to the next one by pressing Jump. Let yourself fall to the last, big grid and go left and up. Wall-jump to grab the first Star Coin. Fall down to the bottom and launch yourself up. This time, grab the uppermost grid and climb. To flip sides, press the Dash button. Go up on the right and flip the grid to come back to the forefront. Destroy the two columns of blocks and go left to grab the second Star Coin. From the coin, go back to the flip, go right and up to the door. Hit the red switch and climb quickly to the door and the third Star Coin. Go through, and then climb up to the left to go through the double doors to Bowser Jr. Destroy Bowser Jr. by jumping on him.

World 3-B
Head right until you come across a red warp pipe that is by itself, below an overhanging red pipe. Go left and up the red pipe on the left side. Grab the first Star Coin, go back down, right, and up. For the second Star Coin, head right slightly and wall-jump between the red pipe and the green pipe to go right and grab the coin. Let yourself down and continue right. Grab the third Star Coin and finish the level.