Your second visit to the Gemini Man stage is going to be quite a bit more challenging than the first, primarily because of the opening area.
As before, you should begin by equipping the shadow blade. Working to the right, you'll see that the floating eye robots now drop ice columns instead of fire. Otherwise, their attack pattern hasn't changed. What has changed is the number of robots. There are far more of them before. Not only that, but there are a lot more holes in the ground. It's easy to get knocked back into a pit if you're not carefully making each jump. As a general rule, don't make most jumps until you've only just defeated a robot. Then quickly jump and be prepared for another to take its place.
The flying enemies aren't your only concern, either. There are others that race along the ground, and they'll just as easily send you to your doom if you're not watching your step.
When you reach the end of this area, you can quickly drop down the pit and to a series of tadpoles encased in bubbles. This time around, don't just take the easy route and go along the bottom; the first set of bubbles will send you to a pit of spikes if you try that. Instead, climb partway up through the bubbles, then slide through. The second and third groups of bubbles present no particular threat, so you shouldn't have trouble passing through those.
Beyond the bubbles, you'll find the gate leading to your first Doc Robot encounter for this stage.
Doc Robot - Flash Man
When you enter this battle, ready the Needle Cannon and start firing for all you're worth the minute it's possible to do so. Doc Robot will start a slow march toward you, and you'll want to have most of his life gone by the time he reaches you.
When he's neared the edge of the screen, it's time to switch positions while continuing the barrage of needle shots. This battle should be short if you're doing things right, even if Doc Robot pauses to freeze you in mid-stride. Whatever you do, don't lose, or you'll be sent back to the very beginning of the stage.
Once you've kicked the first Doc Robot where it hurts, you can proceed through the rest of the stage, which is easier than the first portion was.
Jump over the first pit you see, and keep working to the right until you find yourself at the pool of water. Drop down there, then switch to the Rush Marine ability. Now you need to zip along just beneath the surface of the water, shooting at any robots that come near. Whenever you approach a ledge with a special weapons refill, leap out of the water long enough to grab it before plunging back into the icy soup.
Keep working right, firing to prevent yourself from striking approaching enemies. You'll soon reach a wall, with only a narrow gap at the bottom. Switch off the Rush Marine adaptor and slide through the opening.
Once you're on the other side, leap up to the ladder and climb your way to the next screen. As you proceed right along this corridor, be careful to watch for holes in the ceilings. Robotic bugs emerge from these with alarming frequency. They're easily taken care of with single shots from the arm cannon, but your life will be drained down to nothing if you get lazy.
Soon, you should make it to the ladder on the opposite end of the hallway. Start down it and from there look to the left. There are two holes in the ceiling here, but you can fire at the bugs as they appear from your vantage point on the ladder. In fact, I would advise that you do so long enough to generate a few energy power-ups and maybe even some 1-up icons.
When you're mostly restored, go ahead and cross over to the ladder on the screen's lower left side, and descend to the next screen. Now just cross over to the gate that leads to Doc Robot.
Doc Robot - Bubble Man
If you played Mega Man 2, you should be ready for this encounter. The strategy really hasn't changed. Just whip out your shadow blade, get near enough to do some damage, and let loose.
As Bubble Man, Doc Robot can float around quite a bit. When he does, try to get beneath him. His torpedoes can't hit you then, and since he's rising in a vertical column, it's easy to get in several hits before he descends. Easy enough, in fact, that you might be able to finish him off while only taking two or three hits.
Two of the four Doc Robot stages are out of the way, but you're only halfway through. Time to tackle the next one.
A-1 (red), A-3 (blue), B-5 (blue), B-6 (red), D-2 (red), D-3 (blue), F-4 (blue)
NEXT: Shadow Man Stage