*sigh*...Where to begin?
I guess I'll start with visuals. They do look nice, but I don't really like the style. I'm not bothered by it like
Miranda Paugh is, though. The animation is fluid when the frame rate allows it to be. The frame rate is really the sore thumb of the presentation. Just about every time there's more than a couple of enemies the game chugs like a fratboy. You'll enter a new area with some enemies, one of them will fire at you, you jump to dodge and/or fire back, then CHUGGUGGHUUUG CHUGGA! It wouldn't be so bad if it only happened a couple of times, but it happens in almost every stage. This game could've benefited from another round of optimization.
The audio quality is rather high with the music and sound effects sounding nice on the PSP Go's speakers. I didn't find any of the sound effects or music tracks offensive, but at the same time I didn't find myself thinking, "Wow, that's a great remix of ____-Man's stage." That leaves the voices. Holy shit, I fucking hate the voice acting. It's not like Mega Man 8 where the voice acting was inept, it's just the the voices themselves are annoying and unfitting. Dr. Wily has an irritating shrill which doesn't sound menacing at all, Mega Man sounds nondescript and generic, Roll is saccharine, and Dr. Light sounds bored. The Robot Masters are a mixed bag, but even the okay sounding Robot Masters' voices get tiresome during a battle.
Since I'm talking about the voices, I'll talk about the dialog they speak. It's awful, just awful. What does Bomb Man say when Mega Man encounters him? "BOMBS!" Brilliant!

When it's not basic and bland, it's jerky and choppy. The dialog sounds more like a summary of what the characters say, not what they actually said. To be fair, I did like the split personality Ice Man exhibits before his boss fight.
Now we get to the important bit: the gameplay. I'll be honest, I'd probably hate this game no matter what because it changes the classic game. I might be an old man winging here, but I don't think extra bosses should be thrown in to pad out game length and change the boss order. Elec Man's weakness is the Rolling Cutter, goddammit!
============ I've had this post saved for a while and I don't feel like writing anymore about it, so I'm just going to post a quick closure. If you want to talk anymore about this game, I'll elaborate on my thoughts. ======================
I have three main gripes with this game:
1) The level design
2) Frame rate issues
3) CRAMPS!
I have the same issue Mega Man Powered Up's level design that I did with Mega Man 10's in that it feels like if one part of a level was tweaked a smidge more, it'd be more manageable. There'd be platforms that are just a hair to far apart, forcing you to position yourself at the very edge of the platform and ceilings that're too low. I'll talk about that more in a bit.
The frame rate just frustrates me. I really see no reason for it as this is a console game and it's not the most impressive game, so this leads me to think that this game just wasn't optimized enough. I'd prefer if the game started flickering like the original game.
The levels are too cramped, like the game wasn't meant to be played on a wide screen. There's sections of levels where Mega Man can barely jump.