Origin8's popular tower defense series makes its PC debut this week with the downloadable Impulse release of Sentinel 3: Homeworld.

Originally released for iOS and Android, Sentinel 3 boasts a 20-level campaign and a wide variety of unlockable units, including turrets, orbital ship weapons, and automated drones. The game arrives as Origin8's first PC release to date. A Mac App Store version is also available.

Sentinel 3: Homeworld is priced at $7.99.