When playing Dead Island, you have the possibility to kill a zombie with only 1 hit. When doing this you should progress in the achievement ''One Is All I Need''. The problem is, I am stuck at 1/5 kills. Even if I kill another zombie with only 1 hit the pop up will appear, saying that I killed a zombie with 1 hit, but it still says 1/5 so I never make any progress in this.
Am I doing something wrong or is this a bug? Thanks in advance!