Overall an OK show. The concept is rather interesting and intriguing. The killing scenes are so unreal and stupid. The guards at the world's crossing and the policemen must be a bunch of untrained morons with the way they get killed. I especially found the scene on the 8th episode where they wouldn't kill one of the killers in the no man's land stupidly amusing. The whole 9th episode where a few assassins as workers were able to smuggle a slew of arms into a super high security building was just asinine.
The best thing about the whole show is the masterful J K Simmons. Without him the whole wouldn't be worth watching. Watching 1 season was quite enough.