The game itself is pretty decent. The controls for the plane feel good. The objective is simple enough to understand and execute, though to get all the civilians in normal mode is pretty tough. The audio is good, too.
I have a few quibbles with the art direction, and a suggestion for game mechanics. First, the art: there's nothing wrong with it inherently, but I did notice that all the civilians were different instances of the same white guy, while there were two enemy types with darker skin. I doubt this is something you consciously did, but it is something to consider -- and this could be fixed fairly easily if you just made a few civilians with darker skin to even the playing field, so to speak. And while changing the colors of the outfits on the civilians was a good step to differentiating them, even if you did keep them all the same model, varying up the hair colors would make a big impact, too.
Mechanics-wise, it would have been a nice addition to have the bombs you drop affect the civilians, as well. That would add another layer of planning and strategy, since you don't want to kill the civilians you're trying to save. Right now there seems to be no consequences to just razing the field, which makes the gameplay a bit simplistic.
This definitely has potential, though! Overall, nice job.