One of the classics in the side scrolling-action genre. 'Mega Man 2' is one people will immediately think of when talking about great action games and for good reason. Everything that makes a good game is present here, from a good, iconic main character to amazing level-design to great music and visuals. In fact, the soundtrack is probably one of the most memorable in all of gaming!
The game has the player first choose one of eight stages surrounding a certain theme and ending a unique boss. This boss gives the player new abilities when it's defeated that are helpful in other levels and against other bosses. When all eight stages are completed, the ninth will become accessible, which consists of four more substages. These extra abilities add a certain aspect of strategy as the player could find the best way through these stages by trail and error, or sometimes, decide the order with some common sense.
Thankfully, the game features a handy password system. NES games usually have the problem of having to be beaten in one sitting, but this game includes a clever system that kind of resembles a game of tic-tac-toe in the way it's layer out, but of course this allows for the more complicated password combinations. I should have a stack of papers with drawings of codes on them around here somewhere...
