Growing up, I never had an NES or an SNES. I was an N64 and PS1 Guy. So I never had the chance to experience Mega Man in its purest form. As soon as I found this site. Mega Man 1 was the first game on my mind to play to begin playing NES Games and Catch up to all the games I never got to play. 
I am happy to say that it was worth the wait because the Mega Man Series for the NES is Great. Although its first game was rough, it was the beginning of something Amazing.
Platforming at its finest, tight controls and pixel by pixel movements. The exactness of this game for its time is really something I did not expect.
The graphics of the game are ok for their time it is NES after all and its the first game as well so it gets a pass.
The sound, oh the sound. The Mega Man soundtracks can be used to study music composition because of the way they are made they are so good.
The story is not important here but it grows overtime so that's another pass.
When you start playing the game, it is very difficult at first if you have not played NES Platformers, but as soon as you get the movement and the control you are hooked until the end.
I am happy to say that Mega Man 1 for NES is a keeper for all time.