If you’re a fan of tower defense games, but long for something a bit more three dimensional and interactive, Siegecraft–free today–is just the game you’re looking for.
Siegecraft is a medieval siege game, rendered in 3D, that boasts a much higher level of interactivity than you find in most tower-defense style games. In most games in the genre, you plant your towers and let them fire away. In Siegecraft, you’re actively manning your towers and reigning down medieval projectiles on your enemies. It’s like a mashup of the tower-defense genre and Angry Birds.
The game is, today only (5/23/2012), available for free in the App Store.