On to the new bosses!
One new mechanic worth noting about this bunch is that anyone with a normal jump now bounces away from walls rather than staying against them on contact. I think this is a good choice, making the player think more carefully about where to run even if a boss jumps backward, and allowing the boss to spend more time toward the middle of the room, where it is usually more dangerous.
Blizzard Man can push himself around on his skis, summon four snowflakes in random positions that move toward Mega Man, or roll into an invincible ball and crash against the opposite wall. This is a solid setup for a boss, with his two attacks supporting each other well.
To avoid the roll, the player can jump over Blizzard, or jump against the wall as he bounces away. The former option requires some anticipation, and is harder to do when pressed against a wall. Blizzard is willing to use his skis to push players right up to a wall without contacting them, and while it may be easier to jump straight up during the roll, this leaves the player with less room to dodge snowflakes.
By encouraging players to unintuitively move toward him during a roll and using his movement to take dodging space away, the fight feels uncharacteristically thoughtful for this game and gives players a good range of choice for its simplicity. His only flaw is existing in a game with the charge shot, and leaving the player ample time to use it.
Wind Man also puts up an active fight. He has a pair of projectiles that leave an opening between them at first and close in later, he can pull Mega Man toward himself, and he can take off vertically at different heights to move elsewhere.
Since Mega Man can stand between the projectiles, there was an opportunity here to make the player avoid them in different ways depending on range. They can be jumped at their peak height though, and since Wind Man relies heavily on contact damage, the player is encouraged to stay at range regardless.
There is also a short delay as Wind Man lifts off, giving players ample time to prepare. I had hoped that he might sometimes fly low enough to force a slide, but if he's capable of this I haven't seen it.
This could have been a tough one with a few tweaks, but as it is, the player only needs to worry about keeping distance and jumping the shots now and then. His weakness is also the easiest to exploit, as the player can shoot at any time to deal damage.
Flame Man also gets a simple and dependable move set. He can jump to any position, shoot three fireballs forward, or summon four shot-blocking flame columns from the ground at set distances.
The flame columns always leave a larger opening at the same distance from Flame Man, and learning to find that spot is the key to winning this fight. The columns also appear slowly enough that it's possible to jump to a safe area on reaction. The fireballs are the easier attack to avoid, but Flame Man can use his other attacks before they leave the screen, potentially catching a player mid jump.
This is another solid fight, feeling like a more fair version of Fire Man. His weakness also travels through the flames, giving it a stronger edge over the charge shot.
Plant Man may be a little too simple. He creates a shield, jumps forward or backward at a set distance, throws it, runs forward to Mega Man's position, and repeats.
The shield is small enough to dodge easily and, like Star Man, has a smaller hit box than expected. The only challenge here is in getting used to the wall bounce and jumping over him to avoid being cornered. This is a good template for a basic Mega Man boss fight, but Plant Man needed one more move, or something else for the player to think about.
This is the only boss with a secondary weakness (Flame Man's weapon), but since it is blocked by the shield, the two damage it deals puts it roughly equal to the charge shot. Blizzard's weapon won't hit through it either, but can be lined up well when jumping the shield and can potentially get two hits in before Plant Man creates another.
Once again, we have a good start here: Jumping and two projectiles, one of which is a spread of three and the other moves upward. Tomahawk Man can also take a small step forward to crowd the player and as a sort of fake out.
The problem I immediately notice here is that both projectiles can be dodged with roughly the same timing, and the upward one rarely moves high enough to prevent the player from jumping it. The spread is most dangerous up close and far away, since it appears in front of Tomahawk (fifth image) leaving little time to react, and spreads too wide to jump completely when thrown from across the room.
However, the fight is made much more interesting by the fact that the top projectile of the spread is extremely fast and goes over Mega Man's head, which means that the player will have more time to react if they choose to slide under it. This approach is tempting, but requires paying more attention to which attack Tomahawk Man uses. While the tomahawk could have been stronger with a steeper upward arc, the choice between jumping both projectiles with careful timing or sliding under the harder one makes this an excellent fight.
Plant's weapon fails to protect Mega Man from the projectiles (you had one job!), but this is actually preferable here, as it takes every use of it to finish Tomahawk.
Yamato Man jumps into the air, firing three projectiles on the way down, or shoots the head of his spear forward, after which he has to go get it. The air spread is good, and the way he fires them as he falls instead of at the height of his jump makes them tougher to avoid, since the player has to react to those and the falling Yamato Man at the same time.
Someone must have thought this was too good, as his second attack utterly ruins him. Running to get the spear head usually leaves him open to a free charge shot, and resetting himself against the opposite wall makes his air move easier to avoid if he uses it next. In addition, since he fires the air projectiles so late, there's no penalty to anticipating the horizontal shot and jumping early.
He's still not a complete pushover, but he was so close to being a genuinely hard one.
Knight Man can throw a spiked ball to Mega Man's position, but his real strength lies in his shield and the fact that he can choose to jump or walk forward, and does not hesitate to run Mega Man right into the wall. Dealing with his movement is tough, as he will often stop walking just as a player decides to jump over him, or back the player against the wall, at which point his walk is near impossible to react to.
The ball is almost useless in comparison, leaving him completely open while the player only needs to back away slightly to avoid it. Baiting him into throwing it upward or a long distance makes him even easier to attack. Still, a boss with a Joe-like shield is a good concept, and if he threw the ball a little beyond Mega Man's position it would be much more effective. As it is, the player just needs to take advantage of his jumps to stay near the center and punish him anytime he uses the weapon.
His weakness always hits through the shield, satisfyingly destroying him in seconds.
Centaur Man is a sad followup to Flash Man and Bright Man. He can move by walking or teleporting (using a simple sprite flicker that I can't show here) after which he can choose to freeze Mega Man in place or not.
At this point he fires a single shot across the screen that splits when it hits the wall, which Mega Man is only safe from near the center of the room. Even if a frozen player avoids this, Centaur Man can walk forward just as the freeze wears off, with the player's only option being to hold the opposite direction and prepare to jump. Staying in the middle, walking side to side to avoid the teleport, and anticipating the charge is the only strategy here, which the weakness makes no difference to.
With no limit on the number of freezes he gets or complex terrain, this fight is a frustrating damage race at first and a boring damage race otherwise.
With the exception of Centaur Man and perhaps Plant Man, the bosses in this game all feel like good ideas with just enough flaws to prevent them from standing out. Any would serve as an acceptable boss of middle to low difficulty in a different group, but together in one game, they feel bland. Nobody stands out as the one to avoid, the one to save an E-Tank for, the one to drive the player into a certain weakness order.
They all had a good base idea going and could easily have been made memorable with the smallest tweaks to their speed or behavior. As it is, Tomahawk Man is the closest we get to "the hard one," with Flame Man and Blizzard Man as the more mechanically solid runners up. With the strength of the charge shot and lessened risk of using it, downing them in any order has never been easier.
However, since special weapons aren't the only tools available to us, we're not done just yet.
The Power armor is a strong choice in most cases. Trading range and the slide for two damage per hit, it can damage race bosses easily.
A fully charged shot also pushes bosses back, which can give some breathing room from the corner, bounce a jumping boss away, or stall Yamato Man from picking up his spear. It even hits through the shields of Plant Man and Knight Man. Its only bad match-up is with Wind Man, as the lack of a slide is a significant handicap when being pulled in.
One other oddity of the Power armor is that a half-charged shot deals three damage instead of two. This is a cool reward for precise timing, and possibly the only case where a midway charge is valuable in the original series.
The Jet armor fares poorly by comparison. Jumping bosses are more dangerous in the air, Blizzard Man and Yamato Man's projectiles become harder to avoid, and with no charge shot, flying comes at the great cost of significantly prolonging the fight. However, it is particularly useful for getting out of a corner against Knight Man, and avoiding Flame Man's attacks.
With clever switching, the lack of firepower can be made up for between flights. Given its fantastic edge at platforming, there's no shame in it being less useful here.
In conclusion, here's a silly screenshot of Tomahawk Man mid-headdress-swing.