Tower Siege

Build a tower from the hand you are dealt, then find out whether it stands. Between waves you get four shapes — walls, archers, cannons, mortars, tesla coils — and a short window to place them, and the structural rule is what makes it a real game: blocks without support fall, and falling rubble crushes whatever it lands on. The horde escalates into siege engines that out-range everything you own, so the tower that survives is usually the one built wide rather than tall.