At the start, pass by a few Koopas and you’ll see some Goombas under sets of ? Blocks. After seeing a duo of Paratroopas, more Goombas and Koopas will appear ahead. Cross some landings as you collect the coins and some Paratroopas will appear. Cross a stairway over the hole and enter a pipe to go underground. As you explore the underground area, defeat some Goombas and enter a pipe where a Piranha Plant lurks. Deeper down underground, more Piranha Plants will appear. Enter the next pipe and return to the surface. After passing by a few Goombas and Koopas, cross the stairway and enter the next pipe. In another underwater area, more Bloopers and fish will appear. Enter the next pipe and you’ll reach the checkpoint. A flame will jump and leave smaller flames behind as you cross the bridge. As you navigate flat ground, Hammer Bros will guard the area. Cross the stairway and enter the castle. The corridor acts like a pipe puzzle, so you’ll have to enter which pipe is the correct one. Hit some invisible blocks and jump to reach the platform. Enter the pipe and then the pipe you came from. Pass by a few Paratroopas, go over a lava pit, and bounce off a Paratroopas to enter the pipe on the platform. Cross over lava pits, dodge the fire bars, and enter the red door. During the battle against Bowser, go on top of the cliff above and salvage shells released from the pipe. Bowser will first move around and jump before throwing hammers after taking hits from shells. Don’t jump too high, because there are spikes in the ceiling, and fireballs lurk from the lava. If Bowser is low on energy, he will shoot fireballs and summon small Metroid units. After hitting Bowser with shells 15 times, you’ll complete the final stage. ... https://www.youtube.com/watch?v=YOsB-wj3RAg