diff --git a/actor.py b/actor.py
index 1ec3df3..c88d896 100644
--- a/actor.py
+++ b/actor.py
@@ -82,10 +82,8 @@ class BaseActor(pygame.sprite.Sprite):
         if point < 0 or point > len(self.image_points):
             return (0, 0)
         else:
-            return self.image_points[point]
-
-    def set_image_point_tuple(self, point):
-        self.image_points.append(point)
+            im_point = [self.image_points[point][0] + self.rect.left, self.image_points[point][1] + self.rect.top]
+            return im_point
 
     def set_image_point_xy(self, point_x, point_y):
         self.image_points.append((point_x, point_y))
diff --git a/intro.py b/intro.py
index a8813ac..ca0c5c7 100644
--- a/intro.py
+++ b/intro.py
@@ -13,6 +13,7 @@ except ImportError:
 from state import BaseState, VALID_STATES
 import actor
 import game
+import particle
 
 class IntroState(BaseState):
    def __init__(self):
@@ -35,10 +36,14 @@ class IntroState(BaseState):
 
       image2 = pygame.image.load('gfx/submarino1.png')
       self.submarine = actor.BaseActor(1, image2, "Submarine", True, True, False)
-      self.submarine.set_image_point_tuple((117, 284))
+      self.submarine.set_image_point_xy(117, 284)
       # Instert second animation frame of the subamrine.
 
-      # Create the particle system.
+      self.particle_system = particle.ParticleSystem(0, "Bubbles", 'gfx/burbuja.png', 1000, 1000, 1, -130.0)
+      self.particle_system.set_friction(1.0)
+      self.particle_system.set_gravity([0.0, -60.0])
+      self.particle_system.set_max_velocity(5.0)
+      self.particle_system.start()
       
       if game.DEBUG:
          print "Velocity: " + str(self.sine_movement.get_velocity())
@@ -66,6 +71,8 @@ class IntroState(BaseState):
       self.sine_movement.update()
       sm_position = self.sine_movement.get_position()
       self.submarine.set_position([sm_position[0], self.screen_vertical_half + math.sin(0.05 * float(sm_position[0])) * 42.0])
+      self.particle_system.set_position(self.submarine.get_image_point(0))
+      self.particle_system.update()
 
       if game.DEBUG:
          print
@@ -84,3 +91,4 @@ class IntroState(BaseState):
    def render(self, canvas):
       canvas.fill(self.background_color)
       self.submarine.draw(canvas)
+      self.particle_system.draw(canvas)
diff --git a/particle.py b/particle.py
index aeaf7d9..62f0186 100644
--- a/particle.py
+++ b/particle.py
@@ -7,7 +7,6 @@ import random
 import pygame
 
 import math_utils
-import game
 
 class Particle(pygame.sprite.Sprite):
     def __init__(self, lifespan, scale, texture, gravity = [0.0, 9.8], position = [0,0], initial_vel = [100.0, 100.0], friction = 1.0, frame_rate = 60.0):
@@ -91,9 +90,10 @@ class ParticleSystem:
         self.part_creation_accum = 0.0
         self.then = pygame.time.get_ticks()
 
-        self.gravity = [0.0, -60.0]
+        self.gravity = [0.0, 9.8]
         self.position = [pygame.display.Info().current_w / 2, pygame.display.Info().current_h / 2]
         self.initial_velocity_max = 50 # Pixels per second.
+        self.friction = 0.99
         self.frame_rate = 60.0
 
         self.rectangle = pygame.Rect(0, 0, 25, 25)
@@ -122,6 +122,9 @@ class ParticleSystem:
     def set_angle(self, angle):
         self.angle = angle
 
+    def set_friction(self, friction):
+        self.friction = friction
+
     def update(self):
         # Calculate the time delta.
         now = pygame.time.get_ticks()
@@ -146,12 +149,12 @@ class ParticleSystem:
                                     float(random.randrange(-self.initial_velocity_max, self.initial_velocity_max))]
                         particle = Particle(
                             int(self.lifespan),
-                            random.random(),
+                            max(min(random.random(), 1.0), 0.5),
                             self.texture,
                             list(self.gravity),
                             list(self.position),
                             velocity,
-                            0.99,
+                            self.friction,
                             int(self.frame_rate))
                         self.particles.add(particle)
                     self.part_creation_accum = 0.0
@@ -164,7 +167,5 @@ class ParticleSystem:
         self.then = now
 
     def draw(self, canvas):
-        if game.DEBUG:
-            pygame.draw.rect(canvas, (255, 255, 0), self.rectangle)
         for particle in self.particles:
             particle.draw(canvas)