Ardent Seas blends modern naval combat with classical RTS gameplay, featuring Aliens, space lasers, and unholy amounts of missiles
Developed as a cheaper alternative to the Project 41-class Ballistic Missile Submarine, the Project 21 is armed with Cruise Missiles and Torpedos.
While it can defend itself against other submarines, it's by no means a match for a proper attack submarine, and as such, requires protection, best in the form of such an attack sub.