diff --git a/birdie.py b/birdie.py
index 71c45df..688de52 100644
--- a/birdie.py
+++ b/birdie.py
@@ -4,17 +4,26 @@ TITLE = "Paf l'oiseau"
 WIDTH = 400
 HEIGHT = 708
 
-def on_mouse_down():
-    print('Clic souris !')
-    titi.y -= 50
+def on_mouse_down() :
+    titi.speed = -6.5
+
+def reset():
+    print("Retour au départ...")
+    titi.speed = 1
+    titi.center = (75, 350)
+    tube_superieur.center = (300, 0)
+    tube_inferieur.center = (300, tube_superieur.height + ecart)
 
 def update():
+    titi.speed += gravite
     titi.y += titi.speed
     tube_superieur.x -= vitesse_defilement
     tube_inferieur.x -= vitesse_defilement
     if tube_superieur.right < 0 :
         tube_superieur.left = WIDTH
         tube_inferieur.left = WIDTH
+        if titi.y > HEIGHT :
+            reset()
 
 def draw():
     screen.blit('background', (0, 0))
@@ -28,6 +37,7 @@ ecart = 140
 tube_superieur = Actor('top', (300, 0))
 tube_inferieur = Actor('bottom', (300, tube_superieur.height + ecart))
 vitesse_defilement = 1
+gravite = 0.3
 
 # print(tube_superieur.width, tube_superieur.height)