World 6-2 (Super Mario Bros. 3)
From the Super Mario Wiki, the Mario encyclopedia
This is an autoscrolling level, the progress of the player relies heavily on the Cloud Lifts. Mario starts on a small platform made of Hard Blocks, followed by two small slippery platforms, one of them with an Ice Block and a ? Block containing a power-up. Shortly after this, the player must use the cloud platforms to jump over a column of Brick Blocks blocking the path, then a Koopa Troopa, more Brick Blocks and a very high column made of Hard Blocks, which requires the cloud platforms to pass over it. Afterwards, there are two Ice Blocks and a Coin Block, alongside another Koopa Troopa, followed by more Hard Block platforms, a Brick Block with a 1-Up Mushroom and a Warp Pipe leading to the goal.
In the GBA remake, shortly before the goal, there is a Hidden Block that helps the player reach new ice platforms and two more 1-Up Mushrooms.