Zero Gunner 2

Zero Gunner 2 is a top-down shooter. All backdrops and vehicles in this game are modelled in 3D, though the gameplay mostly follows the conventions of 2D shooters. Since your craft is a helicopter, a "target and spin" feature has been added, whereby you can both rotate your craft to attack an enemy more efficiently, or alternatively lock on a particular point in space and rotate around it while still firing. (mobygames.com)