The Club

On Venice's 7th level Veni Vidi Vici, there is 10 enemies and 5 skullshots and you only need to exit the level with a X15 to get the achievement.

From the start, head round the corner and turn left into the alcove for you first SkullShot, then shoot the guy behind the sandbags and then the 2 at the fountain, there is another skull shot across the courtyard behind some railings, go into look mode and shoot that, then run past the fountain and shoot the skullshot infront of you. Turn right and shoot the guy at the end and back round into the courtyard, shoot the guy who comes up from the bottom and the skull shot above him, then head down these steps.

You should be on X9.

Head left and shoot the shotgun guy for X10, turn left at the end, then right and go straight into look and headshot the shield guy. Run to the end and turn right, look up the stairs and shoot the skull shot. Run up the stairs turn left and shoot the guy infront of you, run out into the yard and turn left and look up at the balcony at the back, you'll see a bonus enemy running from right to left. Shoot him for X14, then shoot the guy on your left in the courtyard for X15 and run to the exit.

Big Thanks to jChaotic for the YouTube link!
Big Thanks to Mr Rodster for the edit.