Alright. Let's get this started.
As of writing this, I have beaten the main campaign as Rockman (which for writing sakes I will now refer as MegaMan, his localized name for convenience, though both will be used interchangeably.)
First of all, some positives I can bring to this character;
First of all, I liked how MegaMan's movement was adapted surprisingly well to SRB2, with his tight jumps and movement was kept mostly intact in this addon.
The weapons are also mostly fun to use, as you can use "Ice Slasher" to freeze enemies and even objects like rings to potentially get to higher places that MegaMan simply cannot reach normally even with his double jump. Hyper Bomb and Atomic Fire also seem pretty fun to mess with, although Atomic Fire seems to be the more friendly fire weapon of the 3. The basic MegaMan lemons are also accurate to how it acts in MegaMan 8 Bit DeathMatch, a fangame I played.
MegaMan's Sprites although taken from said Fangame work well in SRB2, though it is noted that some things may need to be changed in time (i.e. Life Icons on the Monitors and HUD)
Finally, MegaMan's inability to drown does help him succeed in levels where his speed cannot help him reach to a pocket of air.
Now, onwards to the nitpicks and issues I have encountered with Rockman.
First of all is how his gameplay does not work with some of the stages in SRB2's main campaign. Even though SRB2 does have more platforming than other Sonic titles, it does have some things that rely on the character's acceleration and speed, which are things MegaMan simply doesn't have. They are beatable, it's just that things become more harder when MegaMan has a fixed speed and acceleration rate than any other character before him.
His jump also feels... heavier than what I may expect from a standard jump from MegaMan, which does make it slightly hard to reach places with even the double jump. Maybe try to increase his height just a little bit next time?
His slide is also very different than how I may expect it to be. It feels oddly slippery to control at times and isn't really a good way to instantly gain speed as you need to be running to activate it. I feel like this is because the Slide essentially acts as the Spin Dash, which I can only assume is why it works in Deep Sea. Though it would've been easier to allow one of the weapons to be able to break through walls like Amy's Hammer to progress.
The weapons outside of Ice Slasher don't do really much in stages besides doing the same thing the buster has except for doing a bigger radius. I wish these had more stage implementation like bombs being able to destroy surfaces Amy or Knuckles can break or letting them hit bosses harder, though that's probably too big of an ask.
MegaMan also doesn't control like he does underwater, though I feel like it's because of it still being SRB2 and not the fault of the creator.
What I cannot really stand though and hope this will be fixed later on is how MegaMan interacts with certain elements in stages like Moving Platforms, the Zoom Tubes in Egg Rock, the Conveyer Belts, Pulleys, and most importantly; Diagonal Springs. MegaMan doesn't interact with all of these mentioned and possibly more. MegaMan doesn't move with these elements and all and it's essentially forced of the player to move MegaMan around in order to reach the element. It also leads to odd stuff with the Pulleys where MegaMan oddly ascends to if he is still acting like he's being moved by the Pulleys.
Finally, there's sprites that haven't been altered to have MegaMan in them, like the special stage sprites (which I really hoped had MegaMan riding Rush Jet) or the final cutscene fireworks with the selected Character's face on it.
This is still a great character, it's just that there are still some flaws that need to be fixed.
