title: Timing the movement of Sprites
body: <p>I'm working on a balloon pop type of game, where the player has a launcher they can move across the screen and press the left mouse button to fire missile and pop the balloons. What I want to do, is after 25 missiles are fired, move the row of balloons down using the dy property. I've gotten everything to work except for the timing of the movement. The only thing I've been able to figure out, is how to get the row to move indefinitely, but I can't get it to stop. I just want it to move for say a second. How would I do something like that? BTW, I'm using pygame, and livewires if that helps.</p>
  
  <p>This is the module used to define the missile launch when the left mouse button is clicked:</p>
  
  <pre><code>if games.mouse.is_pressed(0):
          new_missile = missile(self.left + 6, self.top)
          games.screen.add(new_missile)
          MISSILE_WAIT = 0 #25
          CLICKS += 1
          if CLICKS == 25:
              a = 0
              while a &lt; 10000000:
                  SPEED = 2
                  a += 1
  </code></pre>
  
  <p>At the moment, I tried using a huge increment counter, but that just froze the game for a couple seconds, and didn't move the balloons. So I'm basically trying to figure out a way to tell python to make SPEED equal to 2 for a certain amount of time.</p>