War of Ages

One lane and a base at each end. Train light, ranged or heavy units, let them march, and take the enemy base before they take yours. Kills pay in gold and experience, and enough of both moves you up an age: stone, castle, renaissance, modern, future. Each age brings better units and a stronger special ability — a meteor shower, a volley of arrows, a cannon barrage, an air strike, an orbital laser. Play a bot on three difficulties, or one friend online.