T-U-R-R-E-T powah! Achievement
Destroy 25 turrets.
Turrets are the large structures that block the path in each lane. Usually, you will have to smash 2-3 to get to the enemies core drill. However, you only get credit for actually landing the final blow on the turret. There's no stat tracking for this one, but to check to see if you got credit for smashing a turret, hit the back button to pull up the current stats.