irem Collection Volume 2 will include shoot ’em up games GunForce, GunForce II, and Air Duel. Whether you played the original on your childhood Super Nintendo Entertainment System or prefer the much-improved Arcade version, we’ve got you covered!GunForce: Battle Fire Engulfed Terror Island can be seen as the initial baby steps that paved the way for the later-released Metal Slug series and its sequel, GunForce II (GeoStorm), both of which were highly acclaimed. Together with GunForce and GunForce II, Air Duel completes the irem Collection Volume 2