import pgzrun

TITLE = "vava bird"
WIDTH = 490
HEIGHT = 490

d = 2
g = 1

def update():
    global d
    if oiseau.y < 470:
        oiseau.x += d
    if oiseau.y < 470:
        oiseau.y += d
    if oiseau.y >= 470:
        print("Game Over")


def on_mouse_down():
    print ('')

def draw():
    screen.blit("back", (0, 0))
    oiseau.draw()

oiseau = Actor("bird1", (20, 15))

pgzrun.go()