ame version converted to a level called "Outnumbered."</li>
      <li>"Outnumbered" has bigger waves of enemies.</li>
      <li>"Outnumbered" has a win condition.</li>
      <li>Three new levels: "Flight Practice," "One By One," and "Pavilion."</li>
      <li>Level selection menu.</li>
      <li>Events can be triggered by checkpoints.</li>
      <li>Better collision detection (using
        <a href="http://gamma.cs.unc.edu/SSV/obb.pdf">OBBTree algorithm</a>).</li>
      <li>More detailed model for enemy shi