No I in team easier for everyone

[Cooljoe]

I found out that you only have to kill a few maybe just one enemy in the level. I got the achievement in the first level. I don't think it relates to the percentage you get at the checkpoints. I think it just means you have to get more than half of your total kills targeting at the same time with the gold above their heads. So if you get three out of four kills in a level with dual targeting and finish it it works.worked for me hope this helps someone.