Use the Mega Buster as Bass
When playing as Bass, take out one of your special weapons and deplete all of its energy. Once you have run out of energy for that weapon, you will shoot Megaman's Buster shots. Note: You cannot charge your Buster as Megaman does.
Recommended Boss order
Defeat the Bosses in the following order: Cold Man, Burner Man, Pirate Man, Ground Man, Tengu Man, Magic Man, Astro Man, then Dynamo Man. Use your normal weapon for Cold Man, Ice Wall for Burner Man, Web Burner for Pirate Man, Remote Mine for Ground Man, Spread Drill for Tengu Man, Tengu Blade for Magic Man, Magic Card for Astro Man, and use Copy Vision for Dynamo Man.
Start with Astro Man, then Dynamo Man, Cold Man, Burner Man, Pirate Man, Ground Man, Tengu Man, and Magic Man.
Defeating King
To defeat Kings' first form, wait until he takes away his shield and throws his cape. Shoot him now. He will then shoot rays shaped like "X"s. Jump over these and repeat the process until Proto Man appears. Proto Man will break King's shield and he will faint. Then, King will pull out an axe. Equip the Energy Saver (E. Saver) and use the Lightning Bolt attack. King will be electrocuted and will not be able to move. Do this until King's life gauge is depleted. King will leave the room and you will have to follow him. He will call upon the flying robot and the tank. They will combine into one big robot fighter. Use your special weapons to defeat it. Use your Remote Mine attack on the wheels. This will prevent him from charging at you. The robot will sometimes shoot homing devices; destroy these before they get to you. You cannot shoot the cockpit.
Defeating King Jet
Use the following tactic when fighting the King Jet in King's Fortress 2. When the King Jet prepares to use the laser (which drains about one third of your health), equip the Blaster power-up (not the Hyper Buster) and fire at the gem as fast as possible (with Bass); o, fire charged shots (with Megaman). Watch out for the fists it fires, as they destroy platforms.
Defeating Pirate Man
Once you get Wave Burner, defeating Pirate Man will very easy. Just shoot him with the Wave Burner and avoid his remote minds/attacks.
Defeating Sniper Joes
Unlike the Super Famicom version of the game, the Sniper Joes (green enemies with a shield that shoot you and throw grenades) have a less advanced A.I. in the Game Boy Advance version. If you jump behind one, they will not turn around. This is a great way to kill them, as long as you clear the jump without being hit.
Burner Man level: Extra Screws
Go to the third location where "Now Saving" appears. After that, just shoot the flying enemies and collect the Screws, Special Weapon Energy, Lives, and Life Energy.
Dynamo Man level: Duo CD
As Mega Man, after you defeat the mini-Boss you will see an area with a spotlight. If you have Rushsearch and CD Finder, jump down and you will see a sparkling spot. Destroy the bats and have Rush dig at the sparkling spot. You will get a CD. If you defeated Dynamo Man and have the exit leave. Either complete the stage or die and save the game. Check your database on number 99 you will see Duo.
Magic Man level: Extra life
When you get near the end of Magic Man's level, there will be train tracks. Follow them to the other side and go in to find an extra life.
Pirate Man level: Push bomb
Use the Wave Burner move underwater on a spiked bomb, and it will push it away.
Recommended Boss order
Use this order to kill the Bosses (with the indicated weapon) as either Mega Man or Bass.
Cold Man: Weakness: Lightning Bolt; Power earned: Ice Wall
Burner Man: Weakness: Ice Wall; Power earned: Wave Burner
Pirate Man: Weakness: Wave Burner; Power earned: Remote Mine
Ground Man: Weakness: Remote Mine; Power earned: Spread Drill
Tengu Man: Weakness: Spread Drill; Power earned: Tengu Blade
Magic Man: Weakness: Tengu Blade; Power earned: Magic Card
Astro Man: Weakness: Magic Card; Power earned: Copy Vision
Dynamo Man: Weakness: Copy Vision; Power earned: Lighting Bolt
Character recommendations
Mega Man: Can do a dash by pressing [Down] + [A]. He shoots a lot slower than Bass, but can also charge his buster.
Bass: Can shoot five shots very fast and in all directions. Does his dash by pressing [Left] or [Right] and he can do a double jump by pressing [A] once to jump, then again in the air. Bass can also do a very far jump by doing a dash, then jumping while still in the dash.
Full life
Before fighting King, equip the Auto Energy (the one that gives you a little bit of life every few seconds). When Protoman comes down to talk to King, do not press [A], [B], or [Start]. Allow the game to idle until your energy is replenished.
Differences from SNES version
In the original SNES version, the Museum stage has three jumping fireballs, but in the Game Boy Advance version has only two of them.