Boss Order/Preferred Weapon to Use
This is the suggested order to defeat the Robot Masters in, as well as which weapons to use on both them and the bosses in Dr. Wily's castle:
Galaxy Man - Use Mega Buster.
Jewel Man - Use Black Hole Bomb.
Plug Man - Use Jewel Satellite.
Tornado Man - Use Plug Ball.
Magma Man - Use Tornado Blow.
Hornet Man - Use Magma Bazooka.
Splash Woman - Use Hornet Chaser.
Concrete Man - Use Laser Trident.
Wall Shooters - Use Mega Buster.
Giant Machine - Use Laser Trident.
Blob Monster - Use Black Hole Bomb.
Dr. Wily #1 - Use Mega Buster.
Dr. Wily #2 - Use Mega Buster.
Dr. Wily #3 - Use Plug Ball.
Acquiring the Rush Jet Adaptor
Instead of getting the Rush Jet Adaptor when defeating a specific Robot Master and assimilating the skill along with that Robot Master's weapon, the Rush Jet Adaptor is earned by Mega Man after any five Robot Masters are slain. When the fifth is killed, Roll and Auto will automatically give Mega Man this adaptor.
General Surviving Hint
There are two specific items that will help you beyond the usual batch of extra lives and E-Tanks that you should consider purchasing with your screws if you're having difficulty. The first item to be considered are Shock Guards, which can be purchased from Auto and Roll and will allow you to survive any unintentional encounter with instant-kill spikes (once per purchase). The other item is called a Beat Call, and will automatically save you from any unintentional encounter with a pit or chasm (once per purchase). If you're having difficulty getting through any given stage, especially in Dr. Wily's castle, consider a visit to the store to purchase these two items to even the odds.
Air Shoes - Beat the game without falling into any holes (the use of Beat violates this).
Almost Invincible - Beat the game without continuing.
Blue Bomber - Beat a boss without being damaged.
Bunny Hop - Jump 50 or less times in a stage.
Bust A Move - Every shot with the Mega Buster must hit an enemy throughout the game.
Conqueror - Beat 100 enemies.
Conservationist - Beat the game by only using the minimum amount of weapon energy (that is, only enough to bypass obstacles forcing their use).
Daily Dose - Beat the game one a day (at least) for 3 straight days.
Destroyer - Beat 1,000 enemies.
Double Trouble - Visit all stages twice and beat the game.
Eco Fighter - Beat a boss only by using the Mega Buster.
Encore - Beat 4 stages when using the same special weapon.
Fantastic 9 - Earn 9 lives.
Farewell to Arms - Beat 4 stages without the use of a special weapon.
Fully Unloaded - Hit a boss at least once with all of the special weapons (only doable in the boss rebattles).
Gamer's Day - Beat the gane 5 times within a day, a day being from 12:00 AM to 11:59 PM.
Hard Rock - Get to a boss's room without being hurt at all.
Headbanging - Beat 8 bosses without the helmet.
Heavy Metal - Get to a boss's room without shooting any weapons.
Invincible - Beat the game without dying.
Jitterbug - Beat the game in under 1 hour.
Last Man Standing - Beat all bosses while one pixel of your health remains.
Marathon Fight - Fight a boss for a length of ten minutes.
Mega Diet - Beat the game without picking up any more than 8 energy pellets.
Mr. Perfect - Finish the game without getting damaged.
Mr. Trigger Happy - Use 500 or more Buster shots throughout the whole game.
No Coffee Break - Beat the game without the use of Energy or Mystery Tanks.
Pack Rat - Collect 999 screws.
Peacekeeper - Beat the game by defeating only bosses and minibosses.
Quick Draw C - Defeat Concrete Man in under 10 seconds.
Quick Draw G - Defeat Galaxy Man in under 10 seconds.
Quick Draw H - Defeat Hornet Man in under 10 seconds.
Quick Draw J - Defeat Jewel Man in under 10 seconds.
Quick Draw M - Defeat Magma Man in under 10 seconds.
Quick Draw P - Defeat Plug Man in under 10 seconds.
Quick Draw S - Defeat Splash Woman in under 10 seconds.
Quick Draw T - Defeat Tornado Man in under 10 seconds.
Quick Draw X - Beat the final boss in under 3 minutes.
Shop A Holic - Purchase 30 items or more.
Speed Metal - Reach a boss's room without letting go of the D-Pad.
Survivor - Beat one boss while one pixel of your health remains.
Tango - Beat the game in under 1.5 hours.
Truly Addicted! - Beat the game 10 times.
Truly Hardcore! - Beat the game 30 times.
Trusty Sidearm - Defeat all eight bosses using the Mega Buster (can also do this with the boss rebattles).
Valued Customer - Buy all items.
Vanquisher - Beat 500 enemies.
Waltz - Beat the game in under 2 hours.
Whomp Wily - Beat the game a single time.
World Warrior - Defeat all types of enemies.