In a world of darkness and lava lurks Shadow Man, the robot master who will fall most quickly to your new spinning powers. He's also cool in that his special weapon is useful. This stage can get quite challenging near the end, but it's really not a long trek if you move quickly and are patient for the last series of death-defying jumps.
The first thing you should do is walk off the ledge to your right, which will drop you down to the next screen. You'll slip past an enemy that is sitting on a ledge at the center of this area, then land on a ledge just below. Quickly drop off to your left and you'll avoid taking any damage. It's not worth your time to shoot this enemy.
In the next screen, you'll immediately want to look right, where mechanical rabbit-like creatures are hopping toward you. One shot kills them, but they're good at avoiding your arm cannon fire. Take them out as you proceed to your right. Just past the robots, there's a bulldozer operated by a hardhat foe, just like the ones you saw in Top Man's stage. Three hits does the job here, just like it did before.
Beyond the bulldozer, you'll find a pit that drops you into a room with a nemesis new to the series, Proto Man. This fellow is like a boss robot. Since you've probably not taken any hits up to this point (or at worst, minimal damage), you may choose to get lazy and just hang out on the right side of the screen, pumping arm cannon shots at Proto Man as he hops about until he takes enough damage and flees the scene. He'll leave behind a blast that makes a hole in the floor, and you'll now be able to drop down it to a lower portion of the stage.
From this new landing, push toward the right. This next area is pretty easy, inhabited by robots that look like giant eyeballs with legs. They use suction cups to crawl along the ledge, and are easily disposed of with a few arm cannon shots. A more dangerous foe is the guy that looks like a walking grenade. Take him out with an arm cannon shot as quickly as possible. Finally, the area will be messing with your vision. Holographic bulbs hang on the ceiling and drape the area in darkness. There aren't yet any bottomless pits, so just keep pressing to the right, defeating enemies and jumping as you find barrier obstructing your progress (you can also use shots to take out the bulbs, but it hardly seems worth the time and effort).
When you drop down at the end of the long hallway into the pit leading to the room below, you're now at the most difficult part of the area. Drop down to the lower level in this room and head right, disposing of enemies along the way. You'll soon come to a pit of bubbling lava.
Narrow ledges form a partial bridge across this area, but you'll soon find that enemies parachute down and zig-zag toward the narrow ledges. You can use three shots to take out these fellows, then hop to the next ledge, but they have a tendency to bump into you and knock you back into the molten soup if you're not careful. Be sure to get in your shots as they're swinging briefly away from you, and don't stand too near the left side of a given ledge or just a slight impact can be instant death.
When you make it across the series of ledges, your life meter is likely quite low. Be prepared for a rabbit that will leap at you in an attempt to decimate the rest of your waning health. One shot will take care of it, and then you can continue right again while dragonfly enemies swoop down. These guys follow a simple pattern you can manipulate to avoid damage. First they drop down slightly from the top of the screen, zip left, then drop again to Mega Man's level, and fly toward him. Rather than engaging them with arm cannon fire, it's almost simpler (and safer) to hop and avoid them.
Past the dragonfly robots, you'll find the gate that leads to the encounter with this area's robot master.
NEXT: Magnet Man