There are more than levels in the whole game, every game there are different with the airships, they are all identified with colors. The six different difficult modes leads you to enjoy the game more naturally from the beginning to the end, take the mode very easy as an example, enemy’s health will decrease 25%, while the damage caused by your maple will increase 25% and there will be an extra bullet for you.
Manual : A and D key to steer vehicle, Left click to fire.