Curlinger is back! This area has a good flow to it, particularly punching the first into the second, and destroying the next two enemies together.
The following split allows for a variety of interactions. While Power Mega Man can punch through the next Shield Attacker, the bottom one comes before the player has another charge ready. This is a spot where the icy floor can cause some damage, but there's enough room to jump the Attacker and let up on the D-Pad just as it appears to coincide with Mega Man's fall, which will prevent sliding and allow just enough time to finish the charge.
Taking the upper platform avoids these two, but they'll be right behind Mega Man as the player deals with the falling Curlinger. This area is no less fun for regular Mega Man, as he can kill the Curlinger under the first Attacker to slide, slide again and jump to squeeze past the next two, and slide once more under the falling Curlinger. The higher Shield Attacker cannot reach the ladder, but adds some tension to the situation.
The vanishing block room is complex, but not too difficult. There are the main five blocks leading diagonally to the gap, a few below that allow for recovery with Jet Mega Man, and an alternate exit to the right.
Taking the normal path leads to a hallway of Brain Breaks. We've already seen these over more dangerous terrain, and the ceiling spikes can be ignored unless we want to try flying over them. I like these guys, but they're wasted here.
It's worth noting that the Blizzard Attack can kill these in one hit.
The alternate path has the same problem: The area does nothing to improve what's been done with these before. If anything, they're easier to handle from below than on flat ground.
This is a little better. The first higher block can serve as practice for safely getting the health, and the last enemy bumps into the ceiling, making it more likely to fall in the pit. Otherwise, the pits can be dangerous if we let Brain Break do its thing, but the game is still throwing the same enemy at us one at a time, and at this point I'm just killing them in different ways to give these images some variety.
The fall to the boss door at least feels dangerous, though we only need to hold forward to reach it.
The boss is an odd one. Tank CSII fires exploding bubbles, constantly rolls forward, and fires smaller arcing shots whenever we're firing or charging our own shots. Only the turret can be be damaged, but hitting this or the wheels will push it back a bit. I don't say hitting anywhere will do this because shots pass right through the middle, possibly due to some sort of system limitation.
Another strange thing about this fight is that getting hit allows us to push it back by sliding into it, and even climb inside through the center, leading to one of the weirdest ways I've been able to fight a boss so far. It's weak to wind, and the awkwardness of having to push it away rewards weapon use more heavily than usual.
The return of the Curlinger section from Blizzard Man's stage is presented well, and the vanishing block room is serviceable. I'm disappointed that Brain Break was both overused and unable to shine here, and I find CSII more awkward than fun, though it does put up a strong resistance against all of Mega Man's forms.