Beacons and Betrayal

Each player controls one of a number of beacon towers on the borders of a great empire. Players must co-operate to signal the empire when invaders are coming, but are also working to improve their own outpost so that they are promoted at the end of the war. Beware, though - if the players act too selfishly and fail to warn the empire, then their homeland will be overrun!
Jam year: 
Non-digital game (board game, card game, physical game, sport, etc.)