I've nearly completed it (I saved just before the 2nd assassin stage), and it's really excellent, and basically entirely playable in english... it does seem like a pretty short game that can be easily completed over a rental though, it also looks like complete shit in most situations (the free-roaming motorcycle driving sequences look like an old PC game from 8-9 years ago running on a Voodoo 1), and many assets are re-used, but we'll forgive Suda as he only has a mere fraction of the budget and manpower that major gaming developers have
it indeed oozes with style, and it doesn't take itself seriously... the dialogue and the wacky characters are fucking hilarious, and the mini-games that you have to do in order to make money (to enter the assassin competitions) are very funny too... most of the stages are somewhat meh, but the hilarious and immensely creative boss fights more than make up for that
about violence, I know that supposedly the japanese version had blood/gore censored, but the game isn't really violent... it's really cartoonish and humoristic in most every aspect, even if there are a few kinda violent cutscenes where bosses die in brutal ways, overall it's pretty silly, to the level of say, the Austin Powers films
it's seriously a breath of fresh air, it's the first killer Wii game I've played... this game deserves a 9.0 at least... the only real flaw that I can think of is that the game is too easy
and by the way, I'm just before the 2nd assassin competition as I said, but... spoiler (click to show/hide)
I can't find a way to enter the baseball stadium again, how to get around this?