Mega Man 2 is an action/platformer that finds the hero battling his way through eight introductory stages (in any order desired) before tackling a final six stages.
The North American version of Mega Man 2 offers two difficulty settings: Normal and Difficult. This guide assumes that you are playing on the easier Normal mode which, if nothing else, is a great way to get used to everything the title will throw your way. The general strategies noted here will work on the harder setting, as well. You'll simply have to be more efficient.
A - Jump
B - Shoot/Special Weapon
START - Pause
Dr. Wily is a mad scientist who uses robots for nefarious purposes. They were meant to clean houses, but now they're helping him to take over the world. His rival, the good Dr. Light, sends Mega Man to vanquish a new group of robot masters and to shut down Dr. Wily for good (which we know didn't happen, since there have been many Mega Man games released since this one).
Special Weapons and Items
When you defeat a robot master, you gain a weakened version of its weapon, which you can then use as long as you have enough energy left. Each weapon requires a certain amount of energy per use, and you can refill it by picking up items that defeated enemies drop along the way.
The various robot masters and enemies all are weak to certain attacks, so you should have fun figuring out what works on whom. That's the key to reaching the end of the game.
In addition to special weapons, you can also acquire helpful items that let you reach new heights. There are three of them available, and they use item energy just like the weapons do.
Progress is saved by way of a password system, which makes it easy to experience the game in new ways if you meet a friend with a password that interests you.
This isn't something that tends to happen a lot now, but it was all the rage back in 1990 or so. Passwords are awarded each time you complete one of the initial eight stages, so you don't lose progress. Though you receive passwords after that point, no password will save your progress beyond the entrance to Dr. Wily's Castle.