A 1992 Game Boy conversion of a 1988 Nintendo Famicom game, Mega Man II is a cut-down version of the original.
Instead of six different bosses (as seen in the Famicom game) there are now four in the Game Boy game. These being: Clash Man, Metal Man, Wood Man, and Air Man.
Each boss character has his own different area, which must be traversed and beaten, before taking on the boss at the end. The name of the boss usually indicates the visual theme of the world, and the characteristics of the enemies.
Mega Man II on the Game Boy is playable and challenging, although – given the choice – I would probably play the original because the scale of this Game Boy remake doesn’t leave a great deal of playing area to actually play in.
More: Mega Man II on Wikipedia