import turtle


def initialize(turtle_shape, bg_color, turtle_color, turtle_speed):
    """
    Initializes turtle instance for turtle game.
    """
    turtle_instance = turtle.Turtle()
    turtle_instance.shape(turtle_shape)
    turtle.bgcolor(bg_color)
    turtle_instance.color(turtle_color)
    turtle_instance.speed(turtle_speed)
    return turtle_instance