Nearly all of the classic series Mega Man titles have been two-dimensional side-scrollers involving horizontal movement through various levels. This mechanic persists even on titles developed for high performance platforms, such as the Sony PSP release of Mega Man Powered Up, which features 3D graphics, yet movement to both the background and foreground is restricted. The main series on both the NES and Nintendo Game Boy would follow this formulaic approach in the design of every game developed on those systems, and set the standard for all platformer Mega Man games to come. Mega Man himself has evolved very little cosmetically since his initial release, but has often been given new techniques in each game. The New Mega Buster, for instance, which was introduced in Mega Man 4, allowed him to charge up a shot. The slide was introduced in Mega Man 3. It was these which were used in order to help him exceed any new challenges added by the programmers.
In the early 2000s, Nintendo of America released a timeline on the official website of the series, which interpreted all stories up to the Oracle games as the adventures of a single protagonist named Link. At one point, translator Dan Owsen and his coworkers at Nintendo of America had conceived another complete timeline and intended to make it available online. However, the Japanese series developers rejected the idea so the timeline would be kept open to the imagination of the players.
The Mega Man series has always been known for its difficulty, but as someone who has mixed feelings on difficult games, one of the things I always loved about the series is most of the games (except a few) were fair when it came to being difficult. This meant either more checkpoints as the series evolved, or short levels like the older titles. This gave the player the opportunity to learn the levels without punishing them and the bosses waiting at the end were usually pretty quick and easy to beat provided you had the right weapon to exploit their weakness.
Down special Default Leaf Shield 2% (circling), 3.8% (thrown) Mega Man summons leaf-shaped units that electromagnetically orbit around him. The leaves block projectiles, and can be fired forwards by pressing an attack button to land multiple hits, or used to deal additional damage to a grabbed enemy. The move is based on Wood Man's weapon from Mega Man 2.