Castle Invasion is the fun, frantic challenge of defending your castle against an army. The king is not a nice gent. He’s given you an ultimatum. Surrender your castle or be throne out. (See what I did there? Because the king sits on a throne. . .yeah? . . . never mind.) What a peasant surprise. With an army of misfits at his beck and call, you’d better pick up that bow and arrow and settle in for some crown duels.