Despite being the penultimate level, it is notoriously difficult and is often regarded as the hardest level in the game. This level takes place in a snowy forest and has the background from World 5. This is the only level to feature Munchers.
Run right to the ice cubes. There are Munchers frozen inside and if a Venus Fire Trap hits one, it defrosts and can give you damage if you touch it. Watch carefully when jumping. Get across the ice cubes and use fireballs if you have them to take out the Fire Trap and ONLY the Fire Trap in the pipe. Your fireballs will defrost the Munchers, too. Jump up to the next cubes and stand next to the pipe here. Jump and hit the Fire Trap with a fireball when it pops out and jump up to the pipe. Run over to the ice cube bridge and hit the ? Block for a Fire Flower and hit the Block above for a 1-Up Mushroom. Drop down and run under the next pipe, then jump up to Star Coin #1.
Get over the next gap and past the pipes here. The Venus Fire Traps in these pipes shoot three fireballs before going back in, so watch them. Jump to the ? Block for a Fire Flower. If the spiked balls get hit by a fireball a Goomba pops out. Drop down and use a fireball to take out the first Fire Trap on the ground. Jump over the three spiked balls while running to make it past. Jump to the platforms with the spiked balls under pipes once the Fire Traps go back in.
Do a small jump over the spiked ball and then run to the next one, and so on. You'll soon reach some stairs. Jump up them to the bridge and hit the ? Block for a Fire Flower, then stand above Star Coin #2 until the Fire Traps melt the bridge so you can drop to it. Or, use a single fireball to melt one of the two ice cubes directly above the Star Coin. As soon as you can, jump back to the bridge on the right and drop to the next pipe. Wait here until the five Fire Traps ahead go back in their pipes and then race across the bridge to the right.
Be very careful of the Fire Bros. just ahead. Run and do a low jump under the first one and use the five cubes above to get some height on it. Jump on its head, then do the same again for the second Bro. Now slide down one of the walls next to Star Coin #3 (depending on what ice cubes are left) and wall jump back up. Get to the second Fire Bro.'s moving platform and jump to the ice cubes in the air, then jump from here to the Finish Flag.
- Star Coin 1: Near the beginning of the level, the first Star Coin is floating above two frozen Coins. Mario and co. must jump up and get it before the Coins are thawed out by any Venus Fire Traps.
- Star Coin 2: The second Star Coin is floating under the long row of frozen Coins, above a smaller row of frozen Coins. Mario and co. must make the nearby Venus Fire Traps thaw out enough Coins to make the Star Coin accessible.
- Star Coin 3: The third Star Coin is surrounded by three rows of frozen Coins, two vertical and one horizontal. After making the nearby Fire Bros thaw out enough of the Coins on the horizontal row, Mario and co. should fall to the Star Coin, then use the two vertical rows of frozen Coins to wall kick to safety.
This level is considered by fans the hardest level in the game.