Tiny Troopers

This achievement requires that you destroy a cumulative total of 10 towers across all plays and replays of all missions. Towers are wooden structures that have one enemy at the top. They have a large health bar, but can be destroyed with a single rocket, single air strike, or two grenades. The campaign will expose you to far more than 10 towers. As long as you destroy each one you come across (and don't just run past them), you should have this before completing the campaign.