World 17-3 (Super Mario Maker for Nintendo 3DS)
From the Super Mario Wiki
World 17-3 is the third level of World 17 of Super Mario Challenge from Super Mario Maker for Nintendo 3DS.
Near the beginning, there is a group of three Brick Blocks and two ? Blocks in between them. The right ? Block contains a Super Mushroom. Under them is a Semisolid Platform alcove with three Hidden Blocks on the top, one of which contains a 1-Up Mushroom. To access the alcove, the player must break three Brick Blocks. There is also a lone Bob-omb and a Pipe that other Bob-ombs come out. Over to the right is another Pipe, but this gives Lakitu's Clouds if the Hard Blocks are destroyed. After a pit, there is a Pipe that spits Bob-ombs and a three-story section with Hard Blocks in between them and at the entrances. There is also a ? Block containing a Super Mushroom on a Fire Flower, a Hammer Bro, and a Key. There is a pit on the bottom floor which, if the player uses a Lakitu's Cloud to go under the ground, will lead the player to a ? Block containing a 1-Up Mushroom which will be destroyed by a winged lit Giant Bob-omb. If the player loses the Lakitu's Cloud, they can get another from a nearby Pipe. In order to continue, the player must use a Lakitu's Cloud to go up before the second pipe with Bob-ombs and unlock the Key Door. This will lead to an area above the second 1-Up Mushroom. There is a Checkpoint Flag near the Key Door.
Now the player must navigate through an area with lots of Winged Lit Bob-ombs and Hard Blocks. There are two Pipes in the area, both of which are blocked by Hard Blocks: the first gives Lakitu's Clouds and the other gives Super Mushrooms. After this, there are a lot of coins above three One-Way Walls which can be gotten from two winged lit Giant Bob-ombs from Pipes. After getting another Lakitu's Cloud from a Pipe blocked by Hard Blocks, the player must navigate an area with many Winged Lit Bob-ombs and winged lit Giant Bob-ombs and Hard Blocks above Spike Traps, some of which come out of Pipes. In the bottom-right side of the area are three sideways Pipes stacked on top of each other. The top gives normal Bob-ombs, while the bottom leads to the sub-area after the Hard Blocks are destroyed. The sub-area is a two-screen area with two Pipes (one containing a Fire Piranha Plant and the other a winged Bob-omb) and three Lifts act like the floor. At the end, there is a bridge and a Key Door surrounded by Hard Blocks. The Key is below the bridge, which the player must throw a Bob-omb to get. Going through the Key Door will reward the player with a 1-Up Mushroom. Back in the main area above the three Pipes is a Pipe that gives three 1-Up Mushrooms one at a time, which will open from the explosion of a winged lit Bob-omb. There are Hard Blocks that can help the player get all three 1-Up Mushrooms as long as the winged lit Giant Bob-omb from a Bill Blaster doesn't destroy them. There are several Donut Blocks and the Flagpole around this area.