Bowser's Treacherous Trek
From the Super Mario Wiki
The level begins with an autoscrolling segment mainly consisting of sideways trampolines and Brick Blocks. After jumping across two Bill Blasters, Mario must jump from winged Shoe Goomba to winged Shoe Goomba until reaching a Flimsy Lift, then hit a P Switch and make his way to a warp pipe. Mario must then smash two Brick Blocks to a Checkpoint Flag. After entering a Warp Door, Mario must quickly hit a POW Block, then another P Switch to obtain a Key and enter a Key Door. After dropping down and entering another Warp Door, Mario must ride some Hard Blocks on tracks, while avoiding Hard Blocks and sideways trampolines moving in the opposite direction. Afterwards, Mario will enter another warp pipe and reach another Checkpoint Flag, along with more Bill Blasters that Mario must jump across. Mario must then quickly make use of a Fire Koopa Clown Car and destroy some of the Hard Blocks, then get across the remaining Bill Blasters and hit the axe to clear the level.