HT Games
Star Man
Star Man is easiest to defeat with Mega Man's default weapon. Star Man can surround himself with a shield and become invulnerable. The lower gravity in his stage will make it easier to jump over him while his shield is up. Hold "B" to charge the Mega Buster while his shield is up and hit him with a charged shot when he drops the shield.
Gravity Man
Gravity Man takes extra damage from the Star Crash power awarded when you defeat Star Man. Gravity Man will constantly reverse the gravity in the room and attempt to collide with Mega Man. You can use his own tactic against him by activating the Star Crash and simply allowing him to run into your shield.
Gyro Man
Gyro Man is especially susceptible to Gravity Man's Gravity Hold. This weapon damages any enemy on the screen when you activate it. Avoid using Gravity Hold in the stage leading up to the boss fight with Gyro Man. Activate Gravity Hold any time Gyro Man is on the screen, keeping in mind that he can quickly fly to the top of the screen and cause you to waste some of the weapon's energy.
Crystal Man
Crystal Man is weak to the Gyro Attack. Not only does this weapon deliver extra damage, it makes it easier to hit Crystal Man as he jumps about the room. After firing a Gyro Attack, you can press "Up" or "Down" once to make the whirling blade change direction to follow Crystal Man.
Napalm Man
Hit Napalm Man directly with Crystal Man's Crystal Eye weapon to deliver the most damage. If you have trouble hitting Napalm Man, you can can also aim at the wall directly behind him and hope that some of the ricocheting shrapnel from the Crystal Eye will make contact.
Stone Man
Use Napalm Man's Napalm Bomb against Stone Man. After Stone Man leaps, he will crumble into a pile of bricks and immediately begin reassembling himself. Time your shot so that it hits just as Stone Man completes his reconstruction.
Charge Man
Charge Man takes the most damage from the Power Stone weapon. It is difficult to time your jumps to avoid Charge Man as he rapidly crosses the room; however, Power Stone does more damage than most of Charge Man's attacks, so you should have little trouble outlasting him.
Wave Man
Wave Man is weak to the Charge Kick. Unlike the other boss's weapons, Charge Man's weapon is not fired with the "B" button. Instead, press "Down" and "A" simultaneously. Mega Man will slide across the ground as usual, but when the Charge Kick is activated a small wave of energy will precede him. Slide into Wave Man when he stops to fire his harpoon.