Appreciate the fan art, even tho I'm not a Megaman fan.
The colors you used are fairly good, even tho in some portraits there are more colors instead of the others. Other then this the rest is "ok".
Since it is a fan art I can't judge the creativity put in it, so I'm gonna stick with an average score.
By the way, it seems that you can use the pixel art very well, and since is a simple "drawing" style, why not trying to create something of your own?
A complete cast of newer Megaman characters would be interesting to see.