Mega Man 2/Wily Fortress 6

You've made it to the final stage of Mega Man II!

There are no enemies in this stage, just acid that drips from the ceiling. Avoid it and make your way to the boss door. The acid hurts bad, so don't let it hit you!

Dr. Wily is an alien! He moves in a figure-eight pattern, firing shots as he does so. He is only vulnerable to Bubble Lead. Don't touch his body, or you'll lose a ton of life. Just keep using the Bubble Lead and being careful, and you'll win without much trouble.

You've beaten Mega Man II!