New Super Bros.: 6-Fort

This tower of terror is filled with spiike pillars coming out of the walls periodically. Platform with good timing and duck to avoid being skewered. The 1st Star Coin is over an alcove to the left. Soon after, you'll reach the midpoint. There's a giant Dry Bones walking around to boost off from to reach the item blocks overhead. As you ascend, you'll find a spring below a set of spike pillars that meet in the middle of the room. Time your jump carefully to reach the next platform without being hurt. As you go up, you'll reach a door. The 2nd Star Coin is to the left and just below the next door you'll encounter. Eventually, you'll reach the boss door. There's a pipe above it, so wall jump up for the 3rd Star Coin. Through the boss door, we meet up with Bowser Jr. once again. The battle takes place on a tilting platform. He's not wearing his mask, so just stomp on him or use fireballs. After you defeat him, he'll carry Peach to the next Fort.