Song-GameDev has announced the release of TowerDefenseToolKit v3.0 for unity. The new version was released today boasting some new features and support for the new unity GUI and other enhancements to make better tower defense games.
Some features that have been added to version three of the tower defense kit are Support for new uGUI, Support for multi-upgrade-path for towers, FPS (first person shooter) mode now added (it's like any fps game minus the movement), Support for mecanim animation and a comprehensive perk system allowing almost any stats on a tower while ability and fps-weapon can be modified via perk now too.
TowerDefenseToolKit is a Unity asset used to create tower defense games. The asset comes with tutorial videos and everything you need to make your own tower defense games.