Mega Man 3/Wily Fortress 5

A very short stage. Grab the power-up items to refill some of your weapon energy. For the coming fight below you'll want Hard Knuckles and Rush Jet, and Spark Shock as backup. Fall to the room below, and begin to do battle with your arch-nemesis.

Dr. Wily
Dr. Wily comes onto the scene in his Pinbot Machine. The machine walks slowly, and quite honestly, doesn't pose much of a threat. On the bottom of the machine, a dangling cannon can be seen. Shoot Hard Knuckles and move them vertically by pressing (or rapidly attack with Spark Shock). You'll win Part One of this fight in no time flat.
 * Phase 1

For phase two, Wily largely continues using the same strategy, but he can now "smash down" with the machine, crushing any would-be attackers. To put Pinbot to sleep, send a few Hard Knuckles into the glass dome holding Wily's control area. To make it easier to hit, you may want to wait until he lowers himself and performs the crushing move. Just keep your distance and let loose with the Hard Knuckles. Another strategy is to use the Rush Jet and just rapid-fire Wily's cockpit with your Arm Cannon.
 * Phase 2