I haven't written a review in a while, so this one is quite overdue. "Mega Man 3", as far as I know, was created by the Capcom development team after they realized that "Mega Man 2" hit jackpot in sales. The sequel was developed, and according to Keiji Inafune, "Unfinished". Let's dive right into it.

Graphics: As to be expected from most sequels, the graphics of "Mega Man 3" are a somewhat better quality than "Mega Man 2". Unfortunately, most of the Robot Masters still look flat, and Mega Man received no changes to his roster of sprites. The new enemies look a whole lot better than the boring "Mega Man 2" enemies, excluding Big Fish, of course. The returning Monking is miles better than the original Monking from "Mega Man 2", and even Hammer Joes look better than their sniping counterparts. I give the game props for the graphics. 
The issue of the "Incompleteness" of the game arises in the graphics as well, as the image of Mega Man on the title screen (the same pose as the Weapon Get screen) is missing in the US release, but present with us Famicom users, which is quite strange.

Sound: Another improvement. Though 2 had an outstanding soundtrack, 3's isn't too shabby either. Songs such as Magnet Man, Spark Man, and Snake Man are amazing and good songs for remixes or just to listen to. The boss music also improved from the non-fitting groovy music of 2 to a more menacing music in 3. Even the fortress bosses gets their own themes now! Again, the game gets props from me.

Addictiveness: I'm not too confident on this one. Although MM3 is undoubtedly fun to speed run with the new "slide" function Mega Man has, the weapons in the game are just a tad awful for them to be of any legitimate use. I cannot tell you how much I despise weapons like the Gemini Laser, or the Spark Shock; weapons that either slow down the entire game and make you vulnerable or do no damage what so ever. People rant on and on about the Top Spin being awful, while forgetting that the Spark Shock does nothing to all enemies and sucks even more. The Gemini Laser is basically toothpaste. You squeeze it out of Mega Man's buster and it slowly oozes at enemies. That's it. The rest of the weapons are mediocre at best, and Shadow Blade leaves a poor taste in my mouth for being so nerfed compared to the Metal Blade. Not fun weapons, I tell you.

Story: Barely any to speak of yet again. The story is all in the manual, and there are something like 2 cut scenes for some story. It really doesn't matter.

Depth: DOC ROBOT. I love them, and they were a great way to extend game time instead of having two fortresses. Other than that, have fun getting the E-Tanks and exploiting glitches to give yourself the Rush Jet Early!

Difficulty: Past the Robot Masters and the Doc Robots, MM3 is too easy. The fortress is painful to crawl through due to how poorly constructed it is, and you get free E-Tanks EVERYWHERE. Even Robot Master Levels get reduced difficulty due to the inclusion of Rush Jet. Overall, it isn't too easy, but it is still far from difficult. Have your kid (or yourself) play MM5 before tackling this and you will be fine.

Overall: MM3 is important. Very important. It introduced Proto Man, it brought us some very cool Robot Masters, and it was a fun experience trying to speed run it. Newcomers should stick to 5 before this one, but it is still quite the easy game. I like it, though it won't win any of my top 3's any time soon.

like mm2, I also have mm3 on my 3ds, its the one I play most nowadays, but I also play mm4 as well as 2&3.