Nice game, though i have some recommendations. Let the player aim or / and move with the mouse. Make missions shorter and make it so that you don't have to blow up every building, and when you transport the hostages to safety. Make it so that you deposit them all at once so that players don't have to wait for too long. Make the levels faster phase or more mythotical and add another mechanic that is essential or helpful to find the hostages, but at the same time gives the game another thing to keep in mind to raise the skill sealing and hinders players from just fly around blowing up every building after defeating the enemies.