A small number of barrage balloons are tethered across a wide area in a simple pattern. Any aircraft which flies into one of the thick cables holding up the balloon will find itself rapidly falling to earth as the tungsten wires slice apart their wings and structure. A barrage balloon is multi-use, but will eventually degrade. Though invisible to aircraft, ground units can easily detect and sever the cables, causing the balloon to float away harmlessly.
Designate a small group of ground vehicles as targets of the Beatdown. While under the effect, they have reduced damage, making them easy prey for your armoured legions. For added hilarity, the other player has no way of knowing a unit is under the effect if they fail to see the original marking. Upgradeable.