Shank is really short, which is why I finished it about day after I posted that I had started it (I just didn't get around to writing a review until now). The game told me I finished it in a little over three and a half hours though that probably doesn't include deaths and such because Steam says I played it for 5.1 hours. Regardless, it's very short and more or less pretty straightforward. You have a few weapons, you beat up a bunch of dudes and then you face a boss. Rinse, repeat.
The good is that the game looks great, and the animation is pretty spectacular, particularly when switching between each weapon as you fight. The transitions there are seamless. I believe they actually hand animated each possible combo, which makes sense since it's the only way to achieve the look they ended up with. The game is also stylish and I like the art style a lot.
The combat is mostly fun but like a lot of beat-em-ups it wears thin after a bit and maybe 75% into the game I kind of started getting tired of it. There's not a heck of a lot of variation to the enemies as far as functionality goes, but they all look different enough that it doesn't matter too much.
The bosses are all pretty cool but with the exception of the final one they're all a matter of biding time until they enter one specific sequence at which point you can grapple or pounce them to take away a big portion of their health. You can spend hours chipping away if you want but that's obviously not really worth it. Repeat four times and they're dead. It's fine but none of them are overly challenging. Though there is one boss in particular (the second to last one) who is a bit quirky. It took me entirely too long to figure out that you can only pounce him from one side, otherwise your pounce will miss entirely.
There's also a slight amount of platforming to be done, though little of it is overly difficult, but it does help keep the game interesting at the end. My major complaint about the platforming is that it almost feels too simple, making it something like a 2D Uncharted 2 where one button does everything and the main character will just grab the only thing he can because there's really no other way to go. Not that I expect non-linearity, but something that makes you feel like you are actually in control of the movement is much more satisfying to me.
There's a story as well but it's mostly a poorly done rip-off of Kill Bill, which I'm sure was not the first revenge story but Shank certainly takes great pains to utilize many of Kill Bill's plot points. Of course cramming five hours of movie into maybe 15 minutes of cutscenes is a bit difficult so it ends up feeling very rushed. In fact it almost feels like they wanted the entire game to be you searching for the first guy and then suddenly more characters are introduced. It ends up feeling sloppy.
There's also the matter of really having no emotional attachment to the characters (including the titular character) so when something bad happens to one of them you kind of don't care. Shank himself is supposed to garner some feelings of sympathy from the player, however he is basically an emotionless killing machine throughout the game, so it's difficult to do so. I realize critiquing the emotional attachment to characters a short beat-em-up is a bit of a pointless thing to do but the game clearly intends for you to care on some level. Otherwise it could very easily play from some kind of campy Bad Dudes angle or at the very least dispense with the flashbacks and reveals and just stay light on the story (nobody would fault it for doing so). It just ends up as a sort of mishmash of something that was intended to be serious but is impossible to take seriously because not enough time was spent on it.
Regardless I enjoyed it enough to complete it (in spite of it slightly overstaying its welcome), so I guess it's a success in that way. I look forward to the developer's next project since there is a good base for a game here, and I have heard from a developer at Klei that they learned a lot from making the game, which is always good news.