From the Super Mario Wiki, the Mario encyclopedia
Mario begins at the bottom of the deep ice shaft and must make his way upwards to the surface. Ice blocks are common here and act as platforms. A ? Block can be seen at the right which releases a Fire Flower. Moving upwards there is a spiked ball moving around the floor where several ? Blocks and Brick Blocks can be found. The Brick Block on the left contains many coins and can be turned into a Gold Block when hit a set number of times. Next, a spiked ball will then drop from above, destroying several Brick Blocks. On the next few levels, spiked balls will continuously roll from the left or right side of the screen. At the top of these areas is the checkpoint. Several Dry Bones appear, followed by a Red Ring. The next area has two fast moving spiked balls bouncing away from walls and each other. On the next level a large spiked ball will begin crashing down and destroying Brick Blocks on its path. Beside it there is a pipe that leads to a coin roulette block and a spiked ball. Another spike ball will then roll down, followed by the exit pipe. Back in the overworld, there are several ice blocks present, which helps Mario reach the top of the flagpole a short distance away.