fix bugs.
Flip the gun and move forward to reach the goal!
When you tap the screen, the gun will shoot and flip forward or backward!
Focus on the tap timing, shoot the enemies, and get high score!
If the gun fly high, it will be hard to control.
If the gun fly low, it will be hard to aim.
You need perfect timing to get high score!
If the gun fall from the stage, you will fail!
Feel free to control the gun however you want!
