World 5-6 (Super Mario Bros. 3)
From the Super Mario Wiki
This is a relatively short level, the player must jump on the Parabeetles found here in order to progress. This level is also autoscrolling. Mario starts on a cloud with some Hard Blocks nearby, after this there are some Parabeetles along with some cloud platforms. Afterwards, there is a ? Block with a power-up, and a Red Koopa Paratroopa blocking the way to some Note Blocks needed for the player to progress, as Parabeetles stop appearing at this point. Shortly after this, there are some Brick Blocks, one of them contains a P Switch, which can be used to turn the horizontally aligned coins into Brick Blocks, thus helping the player to jump safely. On the same area, Flame Chomps start appearing, the player must avoid them until he or she reaches a Warp Pipe leading to the goal, which is being guarded by a Lakitu.