New Super Mario Bros.: 7-Castle

This level involves riding around on snake platforms. The platform will snake around the level and double back on itself, so pay attention. At first, you'll have to dodge the Amps in the area. The first Star Coin is past two of them. After a while, the platform will take you past some Thwomps. Trigger them to fall early so they won't fall on you. The platform stops at a lone stone platform, which is the midpoint. Get off the snaking platform before it falls. There's another snake platform waiting for you. This one will initially take you through an area with spike balls on chains. The second Star Coin is above the anchor point for a ball and chain. Take the platform past it, then drop down onto the Star Coin and the anchor point, then get back on before the platform goes over you. It will then take you to an area with periodically firing jet engines. It will stall in front of the boss door, so let it start to drop, then run and jump to get the third Star Coin before you fall with it. The door will take you outside, where you'll have to climb platforms up to the roof. The boss here is Lakithunder, a Lakitu with bat wings on a gray storm cloud. He throws Spinies, sends down bolts of lightning, and swoops down periodically. When he swoops down, stomp him. Stomp him three times for the key. Bowser Jr. will take Peach to World 8 if you haven't defeated the boss of World 6.