“The Kill Room” (** out of four) was a wildly uneven action comedy that zig-zags from action to comedy to thriller and back again and keeps the audience off balance; a jaded hitman (Joe Manganiello), his boss (Samuel L. Jackson), and an art dealer (Uma Thurman) all get thrusted into a money-laundering scheme involving the criminal underworld and all of them start double-guessing and double-crossing one another. Enthusiastically performed by its strong cast but given that cast and its pedigree, this should have been more entertaining and more fun and it’s not. Film marks a reunion between Jackson and Thurman but does not have the adrenaline rush and sensation of “Pulp Fiction.”