In the late 90's, the 2D fighting game--that last bastion and lifeblood of arcades everywhere--were falling on hard times. Whereas earlier in the decade, Capcom's Street Fighter II and its descendants ruled the arcades and brought in tons of money (admit it--the last arcade machine you probably saw in laundromats, supermarkets, and 7-11s was probably a SFII machine) as the new millennium dawned, they were looking a bit long in the tooth. While there were artistic if not financial successes (Street Fighter 3: Third Strike comes to mind)
Capcom's main competition, SNK and their King of Fighters and related series, weren't doing much better, but less because of creative doldrums (not with games like Garou and the Last Blade series) and more due to finances, which saw the company bought, smashed into the ground, and sent into a tailspin they would spend the next three years trying to get out of.
In the midst of all this, came a game from an unknown (at the time) group Arc System Works and the even more unknown Daisuke Ishiwatari. Ishiwatari's great loves, were video games & heavy metal music, and even those who sucked at fighting games found a game of their own in spotting all the metal references peppered within the game.
Enter Guilty Gear.
For fans of the fighting genre, however, Guilty Gear functioned most strongly as a Third Alternative to Capcom's muddling along whilst lacking in innovation (again, Street Fighter 3 excepted) and SNK's continuing evolution of its various series (which. as much affection, as I have for it, tends to be rather stilted at times) GG was fast, rewarded aggression and played with an energy sorely lacking in fighting games at the time. Moreover, it had an art style somewhat apart from the Big Two. Edgier, and a bit livelier.
Guilty Gear was a cult success on the Playstation, and gave rise to Guilty Gear X, which got a higher profile and actually made it to arcades, the proving ground for 2D fighters. This would eventually begat an entire series of games, which, tragically, made pretty much the same mistakes as the series that Guilty Gear had once been such a welcome alternative to. There were the constant incremental update that promised big things that never broke into the next work in the series, the continuing piling on of more and more layers to the fighting engine, making the damn things so dense and overcomplicated that casual players soon shied away from the games, fearful of needing a 40 page FAQ just to have a hope in hell of winning a round.
So clearly, something had to be done. That this coincided with both Capcom and SNK revisiting their series (now necessitating some innovation, both in terms of updating the 2D fighter for the more demanding HD era and, especially in Capcom's case, making a viable bridge to a franchise whose last game was a full ten years ago) was either coincidence or happenstance means little, what matters is, there seems to be, in this generation of 2D fighters (which, if you'll remember, were supposed to be deaded once and for all a 3D became more cost-effective) is a turn towards freshness, a move back towards accessibility, and an attempt to justify that 2d games can still hang as a viable genre in the late-era of polygons.
Enter Blazblue: Calamity Trigger. Arc Systems Works (now Arksys) decided to point Guilty Gear in another direction and start fresh. Hence, Blazblue, which in many ways has a lot in common with the initial series--it's a fast, aggressive fighter that prizes speed and pressure over turtling and has that same extreme art style . . .
. . .but it also has lush HD graphics, a substantially beefed up story (and story mode--we'll get to that in a bit) and a really wicked sense of humour about itself--seldom do games come with their own sketch comedy parody included as an unlockable, and certain characters constantly remind the player that Blazblue comes with No Fourth Wall Installed (one of the characters, Taokaka tends to face the player and declare various silly things) and the whole game, can at times seem like a parody of 2D fighters, in a sense.
Of course, it's also a pretty damn good fighting game, with an engine that is at once easy to pick up and play and do well with but at the same time has a tremendous amount of depth. Each character has a specific system that can be exploited--for example, Rachael controls winds and lighting, Bang Shishigami has an arsenal of nails that can be utilised for various attacks, Ragna can drain the life out of his opponents, vampire-style. Varying each character's style in such a way--for me, at least--keeps the cast distinct and makes the cast somewhat differentiated from the common types you see in these games (the chick, the speed character, the joke character, the brick, etc.) This, coupled with the smaller cast (12 characters) keeps things distinct, which is a problem occasionally in larger casts.
Visually, it's a feast. Lush, fully-animated 2D sprites play out against hyper-detailed 3D rendered backgrounds. Everything looks fluid and colourful without being "OH GOD MY EYES MAKE THE COLOURS GO AWAY" Mind you, the usual caveats apply here--if you're not a fan of the anime style stuff, this is probably not going to sway you from that way of thinking.
And that brings us to the story mode, which, if the art style looks like anime, the actual story content's soaking in it. Every anime cliche is either hewn to in a tried and true way or (in the case of Bang Shishigami, who is probably everything Dan Hibiki dreams he could be) exploded and parodied and generally not taken seriously. In the midst of all this, or upon fulfilling certain conditions, your character is presented with a branching path in the storyline. Each path causes the story to take a different turn (it's been described as being somewhat RPG-ish, but unless you consider a Choose Your Own Adventure book to be an RPG it's uh, not) If you're OK with these kind of conventions, this won't be a problem. If you're not, the bits that seem to take gleeful delight in deflating those conventions might be to your taste.
In any case--and this is nothing unique to me--people have been saying Blazblue was quite a surprise. Perhaps some of that was due to the soft bigotry of low expectations, some of it was possibly due to its being wedged between two higher-profile releases (KOF XII and Street Fighter 4) and probably some of it's due to the fact that even at it's peak popularity, Guilty Gear was a well-regarded cult hit at best.
However it happened, Blazblue has earned a seat at the table, and I look forward to the inevitable (hopefully) sequel.