Milord, We Have a Zombie Problem

Medieval tower defense against a horde of tens of thousands of undead. Build crossbows, ballistae, trebuchets, dragonfire braziers, storm spires, alchemist towers and sunlance prisms beside the road, aim them by hand and hold the keep while zombies, skeletons, hellhounds, necromancers and dragon-liches pour in. Between battles, spend the souls of the slain in the War Council: a huge upgrade tree with new towers, spells, griffin riders, a holy meteor and heroes who stand guard at the gate.