This is fun to play, and takes me back to my childhood. I definitely see the inspiration from the old game Firehawk from Code Masters for NES. While this is the reason I like the game, it's also the reason I'm docking it a few points (being derivative). Not saying your game is bad, but it's a bit too close to it's original inspiration, but without some of the other intricacies such as fighting off enemy helicopters while rescuing hostages in a completely different mode of gameplay from the main game; much like a mini game you have to win to earn a hostage.
Nevertheless, keep up the good work. I look forward to seeing more content from you of this quality and more, but with some more originality.