It's not the revolutionary title that Hitman was, but that doesn't mean it's a bad game.
Much like the Hitman games, Kane & Lynch's biggest problems are just technical and buggy/clunky ones, that's where the Gamespot scoring hits it the hardest. I personally believe this game deserved a 7.0-7.5 Gamespot score atleast.
The graphics are just as good as in Blood Money, even better with added depth blur and other effects. The game isn't as polished as you'd like it to be. However if you turn on anti-aliasing it makes the graphics a hell of a lot more polished looking. The voice acting is fantastic. The cutscenes and their facial expressions are great, even when you are just standing looking at Kane's face is fun because it's just as alive as Hitman's was in Blood Money. And what I mean by polished is more animational/gunplay wise, not graphical. The gun play can be a little clunky at times but it is well overpowered by the badass feeling you get when using them. Just being in that suit all messed up and bandaged up shooting guys with a handgun is so much fun. And the gun sounds really really sell it well, very nice kicking sounds. The levels are fast paced and fun. Which is another thing you have to remember, this title shouldn't be compared to Hitman. It uses the Hitman engine but is in no way even the same type of gameplay. It's alot more shooting and less being sneaky and blending in with neutral folk.
I would definately reccommend this game to a fan of movies like Heat and Collateral. Because this game brings a different feeling to the table. And the best part is most definately the character's and their personalities clashing throughout the game, it's fun to watch and listen to while playing. Good title, not perfect, but good.