Bomber at War is a 2D World War 2 flying game with 20 different levels. Each level has a target like bomb a submarine or ship. The planes guns, tail autogun, armour, and engines are all upgradable. The game is really good fun although very difficult to complete if you do not fully upgrade all parts of your plane. As missions cannot be replayed it is difficult to get the money needed for a full upgrade, but there is a work around if you restart a mission immediately after completing it you can get money again for that level.
If you ignore the few problems it had Bomber at War is fun gamer and worth playing.