Use arrow keys, mouse move, or touch swipe to control the airplane. 使用键盘左右键、鼠标移动或触摸滑动控制飞机移动
The airplane automatically fires bullets. 飞机会自动发射子弹
Score by hitting enemy planes, game over if hit by enemy. 击中敌机得分，被敌机撞到游戏结束
There are 9 types of enemy planes with different shapes and speeds. 有9种不同形状和速度的敌机