It is not obvious that this game was made in only three days...
It could need some polishing though. I couldn't really tell if I hit an enemy or not. The same goes for enemies hitting the player. The game would have really profited of a system where you keep the shooting button pressed and it shoots automatically.
The controls can also get a little finicky, it would have helped to take away some speed, making the map bigger or moving the camera away a little.
I do have to give you credit though, the graphics, and especially the airplanes, look awesome.
This game is a lot of fun and can be addictive but the polishing just takes away from the experience.