Megaman 8 Codes -

Hint: Extra life:
At the beginning part of clown man's level, shoot a mega-ball into its mouth for an extra life.

Hint: Boss strategies:

To defeat Grenade Man, use the Thunder Claw.
To defeat Frost Man, use the Flash Bomb.
To defeat Tengu Man, use the Ice Wave.
To defeat Clown Man, use the Tornado Hold.
To defeat Aqua Man, use the Astro Crush.
To defeat Sword Man, use the Water Balloon.
To defeat Search Man, use the Flame Sword.
To defeat Astro Man, use the Homing Sniper.

Hint: Rush adapter:
Defeat all Bosses and have all 40 bolts. Go to the third Dr. Wily stage. Just as you reach the top of the stage with a flying robot and are about to go right, there is an opening at the top. Use Mega Ball to reach it. Enter the door and you will have the option to fight all the robot Bosses from all Mega Man games, view a short intermission, or get the adapter.