New Super Mario Bros. Wii Walkthrough Part 7: Hot to Cold

What a sharp contrast of areas. It goes from a desert, straight to a ice world.

Also, I can't believe I couldn't remember how to get the 3rd Star Coin with the Penguin Suit in 3-1. XD I forgot when sliding off an edge you can jump in the air of up to 2 spaces. I left the thought process of that room untouched because I figured me flailing around was funnier than just to cut to the winning run.

Annotation correction corner:
7:39 megaeeveelutions ( https://www.youtube.com/user/megaeeveelutions ), Noah Guerrini ( https://www.youtube.com/user/Nogginoak ) and dortborttzort ( https://www.youtube.com/user/dortborttzort ) mentioned that you just freeze the piranha and jump on it to get the coin. But I had no such power at the time. :P Thanks anyway though!
8:56 Supreme keklord ( https://www.youtube.com/user/SUPAHGamers64573 ), Tre Gibbs ( https://www.youtube.com/channel/UC-ZMNGLOW1BraGcoZ-pRIJA ), Puppyspot 1 ( https://www.youtube.com/channel/UCECDS0dFrEx3hPhQh9MLosg ), Trevor Robertson ( https://www.youtube.com/user/02linkmaster )and zioneig ( https://www.youtube.com/user/zioneig ) told me: You can freeze a penguin, ride it by jumping on top, duck to get through the opening and jump to get the coin as it falls off. Thanks guys!

Time Stamps
0:00 2-Castle

4:27 3-1
12:18 3-2

Enjoy