Glacis

Three wars on one corridor

Glacis is a PC strategy defense game about holding a corridor through three wars, each thirty years apart. You build defenses against successive northern forces, from long-range guns, dive bombers and paratroopers to drone swarms and incoming missiles. Each generation inherits the weapons of the last, but has to develop new answers to its enemies.

Tanks head for your base; other ground units push toward a landmark, such as a church, dam or port. Lose either objective and the battle is lost. Keep both standing, and your lab gains research points.