[1.3.5] Added Rockets and Removed Safe Spot

Rockets, a new obstacle, has been added to the game. At first, a warning sign(exclamation mark) appears and warns of a rocket while tracking the player. Then the warning sign locks and a rocket is launched from that area in a straight line. 

Additionally, the safe spot at the top of the screen has been removed by increasing the spawn range of the crows and decreasing the hight you can go out of the screen.