import pgzrun

TITLE = "Paf l'oiseau"
WIDTH = 400
HEIGHT = 708

def on_mouse_down():
    print('Clic souris !')
    titi.y -= 50

def update():
    titi.y += titi.speed

def draw():
    screen.blit('background', (0, 0))
    titi.draw()

titi = Actor('bird1', (75, 350))
titi.speed = 1

pgzrun.go()