Mega Man has been beloved around the world for over twenty years. Despite more than half of that time spent with no new games, fans have always clamored for more of its distinctive gameplay and charm. Today, the series continues by going back to its roots with the ninth installment to star the Blue Bomber. Sporting graphics that harken back to the 8-Bit era, Mega Man 9 released on WiiWare today with versions for PSN and XBLA to follow in the coming weeks.

As the series has progressed, we have been witness to many changes, with new abilities, allies and villains arriving with each additional game. Despite all of the differences, there are certain core elements that have remained unchanged throughout. It is a testament to the brilliant design of Mega Man 2 that the franchise has enjoyed such longevity.

"Wait," you may be thinking. "Did he just say Mega Man 2? What about the original Mega Man?"

There's no argument that the core gameplay of Mega Man would have been capable of enduring. Its selectable levels, challenging platforming and weapon system are at the very essence of the experience. With that said, there's more to Mega Man that has made for such a classic series and it is my opinion that its first sequel actually sets more than its share of basic fundamentals for what we expect in a Mega Man game. After the jump, I'll explain how.

Let me make one thing abundantly clear before I go any further. While I've never made it a secret that Mega Man 2 is my favorite game ever made, let alone within its series, that is not what this post is about. If you want to read commentary on how the Metal Blade is the best weapon in all the games, you will not be satisfied here. This article is focused on the elements within the game that have become such staples of the series that future titles would feel less like Mega Man without them.

Mega Man's first adventure pits him against the six Robot Masters created by Dr. Light and stolen by Dr. Wily. When Wily returns for the sequel, he has created eight Robot Masters of his own to aid in his quest for global domination. While the increased number may have ultimately contributed to such absurdities as Tomahawkman, for better or worse, this number of boss-themed stages became the standard for all Mega Man games to follow.

Destroying all of the Robot Masters will grant you access to Dr. Wily's castle where, at some point, you will have to destroy them all again. Whereas the original game has you face off against a few of them through the course of the stages devoted to the castle (and the rest in a sequence leading up to the final fight against Wily), Mega Man 2 is the first to feature a "teleport chamber" level. In these levels, each of eight unlabeled teleporters leads to an empty room with one of the Robot Masters. This endurance testing method for encountering the boss enemies a second time has appeared in every game afterward.

While Mega Man's sprites remained the same until the move to 16-Bit hardware, enemies underwent some dramatic changes in Mega Man 2. Most standard enemies, with the notable exceptions of Big-Eye and Sniper Joe, were minimalistic affairs that very clearly indicated their robotic nature. From the sequel onward, the myriad foes that stand between Mega Man and a level's Robot Master take on a more rounded, cartoonish feel that has become a trademark of the series.

Some of the most memorable enemies in the series are massive, robotic animals. Dropping into an empty room, these beasts will completely block your path until you can destroy them. Sometimes the fights can be nearly as challenging as facing a Robot Master and Mega Man will often have to face more than one over the course of a level. The first example of these mini-boss encounters occurs in Wood Man's stage, facing down a fire-breathing robo-dog.

Power-ups, too, found their iconic design in the second iteration of the game. Health and weapon energy pick-ups appeared as more polygonal shapes originally, somewhat resembling batteries or fuses. With Mega Man 2, they take on a simpler, yet more appealing design while simultaneously becoming easier to see. The blinking yellow circle and blue oval are instantly recognizable as being part of the series.

Also added to the games for the first time is the highly valuable E-Tank item. Softening the blow from difficult boss fights, the E-Tank allows Mega Man to refill his health completely. It has returned to save the day in every Mega Man afterward and has even been produced as a branded energy drink in Japan.

There are other aspects of Mega Man 2 which have significantly contributed to the series in ways that, while not series-spanning, are nonetheless important. The canine companion, Rush, is a prime example. While not appearing until Mega Man 3, his purpose as a means of transporting Mega Man to otherwise inaccessible areas and the method by which you acquire his abilities can be traced back to this game. Even the charged-shot attack introduced in Mega Man 4 was previously a function of Heat Man's Atomic Fire weapon.

All of these concepts are, in their own way, integral to what makes a Mega Man. A game which lacked them would be like a game where Wily wasn't secretly behind whatever calamity threatened the peace of Earth. Each additional installment has brought its own contributions to the series which have carried through to the present day but no other has made such an indelible mark upon it.

So, on this day when we are once again graced with the Blue Bomber's presence, I ask a favor of you. Take a good look at the shiny, new game you're playing and realize that, without Mega Man 2, you would hardly be playing the same game at all.