Originally Posted by BipolarGlenn
I'm having the same problem with the 'Scream For Me' achievement. Sent many men flying down elevator shafts, still no achievement.
Well you have to make sure you are reaching a next checkpoint. I know you cant just knock a guy of the edge then die to kill him again. There is one level I am sure you know the one where you can knock four guys over the edge in a row. Just play that one a few times. Make sure at the end of the level, click "Next" and not "Menu". You can exit to menu when next level loads.