Top Man (Use Hard Knuckle)
Shadow Man (Use Top Spin)
Spark Man (Use Shadow Blade)
Magnet Man (Use Spark Shock)
Hard Man (Use Magnet Missiles)
Snake Man (Use Needle Cannon)
Gemini Man (Use Search Snake)
Needle Man (Use Gemini Laser)
You need a controller in Port 2 for this trick. At anytime during a stage, press and hold Up on Controller 2. This will freeze all enemies as long as you hold Up, but it also freezes Megaman unless he is already moving. Also, if Megaman takes damage he'll be unable to move so be sure to stop pressing Up if you take damage!
To start/continue a game with 9 Energy Tanks, go to the Password screen, select the Red balls, and place a red ball in square A6 (upper-right hand corner). This works with other passwords too.
Plug in Controller 2 and hold down the right button. Mega Man can jump much higher, even higher than with rush. Also, if Mega Man falls into a hole he will not die, but will be able to jump out.
While holding down right on controller two, jump into a pit and wait for Mega Man's life meter to empty. You may have to ease up on the right button for this to work, but not for too long or Mega Man will die. Then jump out of the pit and Mega Man cannot take damage from regular enemies. However, the downside of this trick is that after Mega Man's life meter runs out, he cannot use the arm cannon (so make sure you have beaten one boss already) and obtaining energy pellets will undo the invincibility trick.
Holding down right on controller two for high jump and ability to walk across bottoms of holes will not affect use of the arm cannon.