Zero Gunner 2 (2001)

In the near future, scientists working for the powerful Asian conglomerate known as Igem have discovered a new energy source. Refusing to share their technique with the rest of the world, Igem eventually developed a weather control machine named ONI, which they intend to use for the purpose of global domination. A squadron of ace helicopter pilots, called Zero Gunner, is assembled to destroy ONI - but Igem fights back with everything they've got... 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. These actions are not automatically executed, and are controlled by the player; in order to succeed, mastering this feature is imperative. The usual power-ups and boss enemy battles are included in the game, along with a selection of helicopters to choose from.