Not too good but not bad either.
The concept for your series is decent, however I am a bit cynical when it comes to using sprites. I don't hate sprites, but I like to see more effort used when using non-custom sprites.
The animation was decent, however the speed of the sprite movements could stand to be a little smoother. There were times the animations were going too fast or too slow, try to keep it at a more consistant pace.
The Mega Man sprite was also larger than the other sprites, keeping the sprites a consistant size helps keep the quality higher.
Don't be afraid to utilize more sprite frames or create your own custom sprites to add moredepth to your animation. 8-bit sprites are simple enough, it should not take alot of time to make some of your own renditions.
Just as a few minor suggestions to make the quality of your work more appealing, you can try adding a constant background music and animating the backgrounds like in the Mega Man games to get veiwers more into your animation.