We enter Dr. Wily's fortress and give the old man a headache. Nothing unusual here.
Dr. Wily
Stage 1
You'll have to deal with some crusher robots at the entrance to Dr. Wily's lair, so use the Ice Slasher to get past them quickly. Use the Thunder Beam or the Super Fist to clear out the blocks blocking the entrance, and freeze the fire pillars with the Ice Slasher at the right time to make them act like stair steps.
If you need the large health pick-up, use the Magnet Beam to get it. Otherwise, just jump over the spike pits and take the next ladder up.
If you can make it to the top of the ladder before one of the three shrimp bots at the beginning of the next screen hit you, you won't be knocked off of the ladder and into a spike pit. If you need the large health pick-up before the ladder that goes down, get up there with the Magnet Beam and clear the blocks out with Thunder Beam or Super Fist.
The next screen down has some spike traps as well as those exploding bullets flying around again. Don't even bother shooting down these bullets, you'll most likely get hit by the explosion and get nudged right into the spikes. Instead, wait for them to pass on by, jumping over them if necessary.
The next screen down re-introduces the flying platforms that shoot from the side from the Ice Man stage. Instead of a bottomless pit, you have a spike trap at the bottom, which is just as bad. Thanks, Capcom. Use the Magnet Beam here...unless, of course, you're a real man. A real [b]foolish[/b] man. Go up and use the Magnet Beam to get to the next ladder. Make your jumps low so you don't needlessly waste energy for the Magnet Beam on making a makeshift platform you can't reach.
Equip the Thunder Beam and head right to the next room. You're about to fight the Yellow Devil, who would become a Mega Man mainstay over time.
Avoid the blobs that fly to the right, as they take quite a bit of damage.
This is the interesting part. When they make up the entire monster, the red eye in the center of the monster's head finally shows up. Shoot the Thunder Beam at it, and when it connects, rapidly mash on the Select button as quickly as you possibly can. (The Select button let you pause the game without accessing the weapon select, something that is also absent from the rest of the Mega Man series.) Congratulations, you just took advantage of a glitch that does multiple damage on bosses. Try this out on Robot Masters and even Dr. Wily himself when you get there. This will hopefully make the battle against the Yellow Devil mercifully shorter.
Dr. Wily
Stage 2
Three dive-bombing robots will approach you before the first gap, so be careful not to let them respawn while you're taking care of them. There will be two weapon pick-ups at the end. Use the Magnet Beam to get these, otherwise you'll go through the floor and face Cut Man.
Cut Man fights just like he did last time. He's not too hard now, even though you don't have any blocks to throw at him. Just keep plastering him with the regular gun so he's always being pushed back. When you take him down, go all the way to the left to drop through the floor.
Take down the spinning turrets in the next segment with the Thunder Beam. Once again, use the Magnet Beam if you need to pick up the weapon pick-ups here. Go through the floor and you'll face Elec Man.
Elec Man is just as easy (or hard) as he was last time. At least he can't jump over blocks and scare you half to death. The Rolling Cutter will make quick work of him once again. When you beat him, go all the way to the left and drop through the floor once again.
More of those exploding bombs from Bomb Man's stage come out of the bottomless pit yet again. Wait for the debris to explode, then be on your merry way. Go down the ladder, and use the Thunder Beam on the crosses. If you need a 1-Up, use the Magnet Beam to go get it.
Go down here, and you'll meet more crosses. Take them down with the Thunder Beam, then keep to the right as you go down one more screen. Shoot the Thunder Beam at the three crosses and you'll take them all down in one shot (hopefully). Go down the next ladder, and take down all four laser pods with the Thunder Beam with the vertical beam. That'll make short work of them. Going left and using the ladder to replenish the energy for the Thunder Beam with the large weapon pick-up here is well advised. Go down again and you'll deal with three crosses and a laser pod. Take them down, then go down one screen one more time.
You now face the Mega Man clone, and he's really, really, annoying. He moves around a lot, uses the same weapon you have equipped and fires his weapon whenever you do. Go all the way to the left and keep firing the Fire Storm at him. He'll hit you, be he'll go down before you will. If he gets too close, the shield that pops up around you whenever you fire Fire Storm will knock him back. If you run out of ammo for Fire Storm, use the regular gun, as the Mega Man clone can only fire one bullet with that at a time.
Dr. Wily
Stage 3
Take down the crosses and spinning turrets with the Thunder Beam as you work your way down. When you finally make it to the horizontal segment, keep going right and you'll eventually hear water go down the corridor and flood it. Keep going right, as you'll go faster this time due to the current pushing you to the right. Shoot down the penguin-copters and jump over the exploding bullets.
Equip the Super Fist to take down the bubble robots here with the blocks located in the center of the room whenever necessary. The first few are easy to take out with the regular gun, but the others may require the Super Fist as each successive robot here is faster than the last. The last two are really speedy. Their bullets are easy to avoid at the beginning, but that'll be the least of your worries the more you take out, as you won't want the last few bubble robots ramming right into you.
Equip the Super Fist to take down the bubble robots here with the blocks located in the center of the room whenever necessary. The first few are easy to take out with the regular gun, but the others may require the Super Fist as each successive robot here is faster than the last. The last two are really speedy. Their bullets are easy to avoid at the beginning, but that'll be the least of your worries the more you take out, as you won't want the last few bubble robots ramming right into you.