Ngmoco has posted screenshots and a trailer for its upcoming tower-defense game for the iPhone and iPod touch, Star Defense. The game features 3D environments and multi-touch gameplay, and has players control a captain as he travels to a series of planets invaded by alien S’rath forces. Users must examine the terrain of planets to come up with the best defense possible, choosing from a range of turrets with various attacks that include plasma and electricity.

The game features three difficulty levels, seven different planets and five upgradable tower types. A release at the App Store is planned for early May, though pricing has yet to be determined.