pew++

-Now the player will target and shoot only enemies inside the screen.
-The reload time will continue even when they're no enemies so it doesn't count from the start when it spots a new enemy.
-Bullets now get destroyed when they go over the screen borders.
-Changed the Pierce upgrade to now give +1 pierce meaning the bullet can only go through a specific amount of enemies.
-Lowered Player's movement and bullet speed so buying these upgrades has a bit more meaning.