Atoms are color coded: blue are "cold", red are "hot".
As the energetic atoms escape, slowly lower the height of the trap using the slider.
The goal is to get the temperature as low as possible with the most atoms still in the trap.
If you can get the temperature indicator below the "target temperature" indicator you will achieve Bose-Einstein condensation.
You can also "mark" an atom by clicking on it, to make it easier to follow one atom's path.
Once you get the temperature down, click and drag with the mouse to "pick up" one atom and drop it from a height.