From a critical perspective, this film is a disappointment. Jeremy Renner is wooden; Gemma Arterton hams it up. There are a number of things preventing this film from being "good".
But is it "great"?
Absolutely. It's the most fun I've ever had in the theatre. It's bloody, visceral, and deliciously over the top. The under-acting/over-acting dynamic that Renner and Arterton engage in remarkably works. The writing is better than expected, and the film has a number of moments that are genuinely funny. It all comes together to be a mess—but a wild, fantastic, sexy, bloody mess.