The biggest installment of the award winning Sentinel sci-fi tower defense series now on PC! Take the fight to the alien homeworld and unleash a massive arsenal of weaponry. Get up close and personal on the battlefield in your power armor to execute devastating attacks and support your defenses! * An epic campaign across 20 levels. * A powerful commander unit which can level up and gain new abilities as you play. * Over 20 unlockable turrets, orbital ship weapons, automated drones and abilities at your disposal. * Customize your weapon loadout in the Armory to match the demands of the mission. * NEW : Includes new content featuring new commander, enemies, campaign, weapons and more! * Endless modes for all maps. * NEW : Steam Achievements * Classic mode allows you to compete for scores in a pure skill-based game mode. * Exclusive music by Specimen A.