Spec OpsG 5

Spec Ops G5:
Kill 50 Enemies with Delta Force

This achievement requires that you get a cumulative total of 50 kills with the delta force trooper across all plays and replays of all missions. The delta force soldier is a special trooper that can be added before the start of the mission. He costs 70,000 CP per mission and isn't available until Mission 21. If you use the Delta Force trooper several times in campaign, you may unlock this before completing the game. Otherwise, you can load up Level 23, purchase the Delta Force trooper, and kill as many enemies as possible. Repeat the level, if necessary (purchasing the Delta Force trooper each time), until unlocking the achievement.