Combined Op Successful Achievement
Combined Op Successful10
Completed a COOP mission with a teammate
Although you can work on certain COOP missions by yourself, you will want to find a partner who will play through at least one of the missions with you for this achievement. Kobin and Grimm's COOP missions are all about stealth, while Charlie and Briggs's are a mix of both stealth and combat. Upon successful completion of a single COOP mission with your partner, the achievement will unlock for you both.