Here's the easiest, most trite-yet-true call any critic will make this year: If you liked (or, at least, "appreciated") "Crank," you will feel largely the same was about it's sequel. It's as simple as that. The only mandatory note of caution is that, since the first film's impact (such as it was) had a lot to do with the way it arrived as a bolt from the blue with no real warning as to just how insane and yet alarmingly well-made it was, the sequel is almost by-design going to be ever so slightly less mind-blowing because... well, this time you kinda of know what to expect. Give it credit, at least, for swinging for the fences in it's attempts to one-up it's predecessor.
For catchup's sake: "Crank" was a one-part celebration, one-part satiric deconstruction, one-part adrenaline-injection of yer basic "boy vs. the world" macho action epics; specifically the type in which it's star - British character actor turned surprise B-movie action god Jason Statham - was/is currently making his bones. It related the purported "final day" of one Chev Chelios, your basic unstoppable one-man-army hitman antihero who awoke to find himself injected with a lethal poison that will kill him unless he kept his adrenaline constantly ramped up - requiring him to use everything from pain, drugs, caffeine, sex and whatever else you could imagine to keep himself alive long enough to take revenge on his "killers." The story climaxed with what appeared to be Chelios' spectacular "death," but you know how action heroes are...
The first film had energy and style to spare, but whether or not it was meant to be anything other than "awesome" is largely in doubt. If you WERE to go looking for a sense of presentation theory, I suppose a good way to describe it would be that the film seems to imagine a theoretical "ideal audience member" for itself in the form of a mad-at-the-world teenaged boy and views itself through "his" eyes: Chelios wreaks bloody havoc through a "people and things who piss me off in L.A." obstacle course in which everyone and everything has it's worst foot forward practically begging to be throttled, and our view of it is a multimedia blitz of pounding music, gratuitous sleaze, dehumanizing caricatures of every race, gender and lifestyle to be found and a smattering of video game sound effects.
In the sequel, Chelios is "saved" from his death by a gang of Chinese Triad organ-thieves who want to steal his demonstrably-unkillable heart for mysterious purposes. Outfitted with an artificial heart that requires constant replenishment of electricity, Chev is once again off-and-running across the City of Angels to punch his way to retrieving his "property," stopping only long enough to electrocute himself in whatever oddball way can be found to keep on kicking. Along with the Triads and a rival Latino gang with it's own agenda to fight and Bai Ling as what is either the most offensive Asian female character in modern film history OR a bloody-brilliant satire of stereotypical Asian female roles in Hollywood movies, just about every minor character who survived the first film (and some who didn't) are back for another round as well.
It's not really a complicated thing, guys: Either you WANT to see likable action lead "Double Dragon" his way through nightmare visions of the day-to-day annoyances of sharing urbania with the rest of humanity with an almost Troma-level disregard for basic decency visualized in a manner so impressionistic it borders on the outright surreality one might expect from a Michel Gondry or Jan Svankmajer piece (at least one fight scene briefly morphs into a 100% different genre and visual style that's destined to make it a "no, really!" classic) or you DON'T.
One thing I CAN offer in it's favor is that, for all it's "fuck-everyone-and-everything" bluster it's consistently hard to figure which targets filmmakers Neveldine and Taylor aim to skewer and which they aim to (in their own way) celebrate: At one point, a big-bossomed stripper participating (topless) in a gun battle takes a nonlethal bullet to the chest and, rather than blood, we're treated to the sight (and sound) of liquid silicon erupting from her punctured implants... on the other hand, Chelios' eventual backup is an army of musclebound, leather-clad African American gay/S&M bikers who arrive on-scene in a thunderingly-heroic manner usual reserved for literal cavalry. If nothing else, it's a genuinely peculiar blend of screw-the-world misanthropy and quasi-progressive caricature-subversion. There's certainly nothing else quite like it out there right now.