I will add that while the games don't seem to be that good, the movie is actually decent (you need to level your expectations here). Eri Otoguro is an absolutely beautiful woman and she is wonderful to watch playing Aya -- as ridiculous a character as Onechanbara is, the movie actually treats the subject matter with a certain level of seriousness and it's better for it.
As for the games, I think the Onechanbara review at 1Up.com is one of the greatest reviews I have ever read. I highly recommend you give it a read. And yes, 1up.com gave it a B.
http://www.1up.com/do/reviewPage?cId=3172908&p=4
BTW, Scott Stanley (the reviewer) is awesome!
For those too lazy to click on the above link:
"Onechanbara is one of those titles that could have used, well, a better title. In Japanese, sure, it means something like Big Sister Sword Fighting, but even that isn't saying much, and nobody this side of the big wet thing is going to know what the hell it is. Mostly it just looks like the only word I have the letters for when I'm losing in Scrabble. Giving it the subtitle "Bikini Zombie Squad" is a step in the right direction, but I half wish they'd just gone all the way and called it "Underpants Zombie Killfest: Bloody Jubblies."
I have a significantly less-than-secret love for D3 and their Simple 2000 series. Mostly because once they got past making straight up budget genre crap like The Tank and The Shooting they moved on to insane genre fusions like survival horror bass fishing, survival horror dating sim, and survival horror ambulance driving. Hell, they were responsible for Earth Defense Force -- a game entirely predicated upon blowing up thousands of ants, spiders, buildings, and anything else I've ever felt like screwing the hell up with a rocket launcher. They've been cheap, they've been dirty, and they've been games where I could write a laundry list of their shortcomings if I cared to. I don't, however because at the heart of them they've been about one thing: doing something stupid that I want to do. Hell, "Undead Undressed: Fuku

ing Funfest" has a hot blonde girl running around wearing nothing but her lingerie and a gun belt, splashing barefoot through puddles of zombie guts. Throw in some Van Halen and a motorcycle and it's pretty much the picture of my middle school wet dreams. Actually, it has a motorcycle, so it's five sixths of the way there.
Yeah, it has its weak spots. The plot is vapid nonsense that's actually worse than throwing a bunch of girls in their underpants into a zombie killing spree with no excuse at all. The unlockable costume parts depend on repetitive bullshit that you wouldn't go through the trouble of doing even if the game had the grace to tell you what you had to do beforehand. The translation is an absolute mess -- I know that people get a little crazy naming their kids these days, but I've yet to see anyone who has named a girl Annna with three Ns. And the gameplay consists of killing literally thousands of nearly identical undead shamblers with the occasional not-very-hard boss fight. But, you know, I like killing thousands of staggering, rotting idiots. I'll do it for hours just for the sheer, stupid glee of it. Doing it while giggling at the ridiculous breast physics of a chick wearing a straw hat, a feather boa, and a bikini is just gravy at that point.
Of course, you have to suspect the thing of pandering to that loathsome lowest common denominator. Putting random tits into a genre is the kind of thing that got us Hooters: Road Trip, after all. But then again, there's something to be said for the lowest common denominator. They like beer and cars, but just because their interests tend toward Natty Ice and Nascar doesn't mean we should write off scotch ale and driving an Astin Martin down highway one. Underneath what seems like desperate sexploitation, "Bikini Zombie Killorgy: Crimson Tatas" is a passable little kill-shitloads-of-zombies-and-collect-glowing-orbs action game. And there's even some character customization with sexy dress-up options thrown in for anyone who likes to play with Barbies while they're cutting up thousands of undead guys.
Then there's the plain weirdity of it. Admittedly, women are damn scary things, and they're prone to occasionally bleeding all over the place and flipping out and killing everything nearby. I've never seen this kind of gynophobia taken so literally before, though. The protagonists of this game, when their flashing red killcrazy meter fills up, begin bleeding from every part of their bodies, which somehow enables them to turn into rampaging engines of destruction. The bare-bones manual offers no explanation for this. The first time it happens you'll be reaching for your copy of "Are You There, God? It's Me, Bikini Zombie Killchick." The second through five-hundredth time, you'll just be thinking that the people responsible must have serious goddamn girlfriend issues. And you probably will, too, if you ever let her see you playing this thing.
So yeah, it's stupid. It's brutally stupid, to be honest. But "Underpants Deadguy Cutters: Ultimate Tittykill" has enough game to keep you going for a few days, and it sells for twenty bucks less than usual. Honestly, I don't know why big breasted women wading through gallons of blood took so long to get to America."
Like I said, Best. Review. Ever.