Third Course (Nerve-Wrack Pack)
From the Super Mario Wiki
At the start, Mario can collect a Gold Flower before using the Pipe Cannon to move on to the next area with the Warp Cannon. After being fired from the Warp Cannon, Mario must stomp on Bullet Bills to make it though the entirety of the level. A Gold Ring can be found on a low platform.
If Mario goes to the left of the Warp Cannon, another Pipe Cannon can be found that leads to a different Warp Cannon, which in turn leads to a more difficult stage. This is also the only way to find the Star Coins.