New Super Mario Bros. U: Frosted Glacier-3 -- Prickly Goombas!

Some of the Goombas in the level are protected by a flammable spiky shell. Not only do you get the Fire Flower in this level, but there are lots of Fire Piranhas. Fireballs destroy the spiky shell, releasing the Goombas. Go through the pipe guarded by three Goombas for the first Star Coin. There are invisible blocks on the sides. Return to the main level and you'll soon reach the midpoint. To the right of the rolling hill, under a ledge, you'll find Yoshi. Go past the Fire Bro and flutter to the right to a pipe. Once you go through it, bounce off a Goomba in a spiky shell to reach the second Star Coin. The third Star Coin is over the platform over the Goomba in the spiky shell and the Fire Bro. Jump from the ledge to the right to get it. Pass another Fire Bro and navigate a maze of Piranha Plants on a rolling hills to the flagpole. This opens the path to Frosted Glacier-4 and -5.