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! Features 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.