Well....I finished up Mega Man 5 last night, while rocking an 80's get up haha. I'm crazy. 
Anyways, after the experience was over.........I was actually a bit dissapointed, I mean I guess it was alright but it just didn't feel like the same Mega Man I grew up with regarding MM1, MM2(especially) and MM3. MM4 for me was the starting point of Mega Man getting stale, while I had some pretty sweet memories of 5 growing up with my best friend. Blasting through Crystal man's stage, or plowing through Gravity man's unique gravity based stage or blowing down Robo chickens in Gyro man's air stage ect ect.
I mean here's the thing, i really like most of the organic and outside stages in MM5. Gyro, Napahlm, Star and probably Crystal had the best stages. There were those unique spin platforms that would spin MM around which was new to the franchise, and Gravity man's stage was creative all on it's own. But for the most part, the stage design wasn't exactly genious or that creative, it all felt rather bland and sub par.
But yup! There are 2 or 3 glaring flaws or things i had a problem with MM5. Which caused me to play a bit sloppy, careless and leading to boredum mid way through. The challenge just isn't really there....The fact that you're thrown 1-ups and E & M tanks at you like pennies was ridiculous. The boss battles annoyed me, not only because they were so easy but because MM5's bosses are configured or based around Mega Man's super buster shot.....In MM1, 2, 3, 9 and 10 each tiny pea shooter shot would take one little snippet of damage off of the boss's health meter which not only felt satisfying to do, but uh....It made sense! 
In MM5 however, that doesn't happen.....If you blasted 5 pea shooter shots rapidly and hit the robot master with all of them, it would only register 1 hit, while the Robot Master starts flashing waiting to recover. It's total BS. So you're forced to use the Buster shot.
The same deal goes for the stages, since many of the enemies aren't 1 shot kills like in the older MM games, forcing you 'again' to use your buster shot....Which i stilll rarely used. That aside, the music was just weak....It all started to sound the same. Gyro's sounded almost the same as Napahlms, i couldn't tell them appart in the beginning.lol None of it has that upbeat amazing catchy ness of 2, 9 and even 3 or 1. It's not up to MM standards at all and most of it sounds fitting for a space themed stage. The stand out for me was Wily's Castle theme. Plus i kind of fug Concrete, Star and maybe Gravity man's. None of it was bad perse, it was just....well, passive.
Wily's Castle however i found to be pretty solid, and i enjoyed the bosses as welll.. Although Wily's final form was too easy....Hell, that's MM5's biggest problem, it's just TOO bloody easy, the music is spacey and mostly forgettable, the stages don't exactly have their own unique set of enemies as they're seen in many of the other stages which makes the game seem jumbled and rushed. When you face off against the RM's for a 2nd time in Wily's Castle, you're instead sent back to their levels boss room instead of Wily's Castle room? Maybe it was totaly intentional, but it seemed due to being rushed.
Mind you, i hardly used the Buster Shot and i made the experience slower and more tedious and difficult....MM5 is based around the Buster shot, at least the bosses are for the most part, and i didn't roll with it, as to why i'm going to start up another game tonight and play it properly. PLUS i was getting a bit tired and bored with it, and took the whimp route and used a bunch of e-tanks instead of mastering the later bosses patterns, which is so unlike me. AND i missed the 'G' in Mega Man.
I'm sure I'll have a better time with it tonight, but based on this playthrough i found it to be just decent, AND the easiest MM game I've ever skimmed through period.

. Just the fact that it wasnt popular probably will keep it from coming to the Wii or WiiU and the fact that it wasnt original released for a Nintendo console.