You've now arrived at the last full-length stage in the game. After this point, you'll spend almost all of your time battling bosses (most of them familiar) and then you'll be to the game's end. So steel your nerves and get going.
As you head to the right, the first enemies you'll encounter are the bulbs that like to drop from the ceiling and rush you as you draw near them. You'll have to deal with a few of them as you ascend a series of steps. Charge shots are more than up to the task.
Next, you'll drop from the top of those steps and head along a corridor with a low roof. There are spikes along the floor here in a few spots, including right at the end, where you need to be especially careful to make a good leap to clear them. If the enemy is still in position, it could knock you back and you could recover in time to jump free of the spikes. Or you can use the Rush Jet as a temporary platform to definitely clear the spikes, if you think they might give you trouble. One way or another, you should head down the shaft at the corridor's end.
Now you'll drop into a lower room, and from there you can drop through another gap. Here, there's an E-Tank on a ledge to your upper left, so grab that if you need it and then drop down to the room's lowest level and advance toward the right.
You'll encounter some circular ledges here with enemies rolling around them. There's a wide gap you must cross, so now is a good time to bring out the Rush Jet. You can ride it past the first set of wheels and then reach a horizontal ledge. Then you can ride it again to pass a second set of the wheel-shaped ledges, while also steering clear of the ceiling and its spikes.
Switch to your arm cannon then and advance as you take out a few hardhat enemies. Then you can climb a ladder to reach the next area.
In this next room, there are two more hardhat enemies. Take care of them and then climb yet another ladder to reach a corridor leading to the right. As you head along it, you'll need to battle more hardhat foes. These are the sort that break up into several miniature versions of themselves when you blast them, so be ready to follow up with a few extra shots to clear the way.
Past those hardhat foes, you'll drop down a shaft and land near a narrow bed of spikes. To the left, armored bats hang from the ceiling. Let them start to approach and then take them out with charged shots. Leap over the spikes and drop to the room's lower level. Continue toward the right from there and find more rats and bats, but nothing you can't handle. Then you should drop through an opening.
To your left now, you should see a large energy capsule. Collect it if you need it and then head right. There's a rat here, and beyond him a series of ledges that function as stairs. At the top, there's one of the rooster-like robots that sends little egg-shaped fellows after you. Defeat him in the usual manner and climb the ladder he was guarding.
The next room houses a giant robot that moves like the giant pink fellows you've encountered in the past. This guy is green, though, and he starts things out by lounging on a bed of spikes. When you start toward him, he'll jump toward you and you'll probably take damage as you eliminate him. Of course, you could instead just use Beat and take him out while you cling safely to the ladder.
Once that robot is toast, use the Rush Jet to reach the high ledge and ladder, which you can climb into the next room to find another such robot (again, Beat works wonders) and the gate that leads to the boss encounter.
This fellow looks a bit like an oversized hardhat, and he's about as vulnerable for most of the fight. The only time you can hit him is when he lifts the shields on either side of his protective, bubble-shaped cage.
As the fight begins, charge up your arm cannon and worry first about not colliding with your adversary. He takes up a lot of screen real estate, and he likes to swoop slowly toward you if you're standing along the far left or right side of the area. Always be ready to slide rather than letting yourself be pinned.
There are two gray platforms in the area, which occasionally rise. You can use them to gain some elevation, and to fire charged shots through the openings when your foe lifts the flaps. A charged arm cannon shot actually does a lot of damage, and Gyro Man's gears are even more effective.
As the huge enemy moves back and forth, up and down, he'll sometimes also launch orange balls that travel in high arcs, but those are easy to see coming and thus easy to avoid. Mostly, you should worry about positioning yourself on the gray ledges so you can easily jump and fire shots with your weapon of choice. Don't be afraid to use an E-Tank if you need to, since there will be another one waiting for you at the start of the coming stage… though this fight is simple enough that if you act quickly, you may be able to clear it just fine without relying on that resource.
NEXT: Stage Three