You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information.
<?xml version="1.0"?>
<api>
  <query-continue>
    <alltransclusions gatcontinue="Infobox_Game|85" />
  </query-continue>
  <query>
    <pages>
      <page pageid="34" ns="0" title="GAMES:Test Drive" />
      <page pageid="60" ns="0" title="GAMES:Doom" />
      <page pageid="62" ns="0" title="GAMES:Test Drive III" />
      <page pageid="64" ns="0" title="GAMES:VRStudio" />
      <page pageid="65" ns="0" title="GAMES:Realms of Arkania: Blade of Destiny" />
      <page pageid="66" ns="0" title="GAMES:Realms of Arkania: Star Trail" />
      <page pageid="67" ns="0" title="GAMES:Realms of Arkania: Shadows over Riva" />
      <page pageid="69" ns="0" title="GAMES:Brain Dead 13" />
      <page pageid="70" ns="0" title="GAMES:The Oregon Trail" />
      <page pageid="84" ns="0" title="GAMES:Syndicate" />
    </pages>
  </query>
</api>