Wow amazing little game. I love every aspect of this one. Simple but very playable and no confusing at all.
Graphics is good. If you are interested I can suggest 2 things (and plus a bug maybe not sure) that I think can make this even better:
1) perhaps allow some kind of guide line so player can aim. I know... it make the game easier, but perhaps that's a good thing to start. Then later, you can have a radio call in to control tower letting you know something damaged the tracking system so at least player can get a taste of success at beginning then the difficulty just rise :)
2) this i am not sure, but perhaps give player some target tracking missiles with limited supply of course so at least we can shoot down some "drone" LOL this game totally reminds me of what's going on currently in the world. Bases are undefended against drones!
3) this last one not sure maybe a bug, so at the end of the game when i try to quit, the quit button don't do anything so I am not sure.
But all in all, this is a good fun game for me to play. Enjoyed it.