New Super Mario Bros.: 7-Fort

This fort has moving spike walls to make the level interesting. Take the red pipe up, climb up, then drop down to the right to the get the first Star Coin. To avoid spikes, duck while jumping up the spiked stones. There will be a stone moving left to right. Go into the alcove above while it's moving, then drop down between the spikes so it will take you to the other side. There are retracting stairs with spikes which lead to a door to the midpoint. The door will take to the next area. Here, you'll have to dodge moving spikes and crushing stones. Hop over the vertically-moving stones, to reach the second Star Coin. There are four moving spiked stones above. They will either move into the formation of a diamond or square. Move when they're a square to avoid being crushed. Just above, a series of stones will move into place to block you from reaching the boss door and third Star Coin. Move quickly and get out of the way, or into the boss door to avoid being crushed. Bowser Jr.'s wearing his mask and the battle takes place on a moving stone slab. Use either the shell he throws or fireballs to take him out. He'll run off with Peach to the castle after you defeat him.