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="Ep_Wh_Q" />
  </query-continue>
  <query>
    <pages>
      <page pageid="5300" ns="10" title="Template:Centurion Achievements" />
      <page pageid="5212" ns="10" title="Template:Currency selection" />
      <page pageid="5048" ns="10" title="Template:Dauer Palastbau" />
      <page pageid="1735" ns="10" title="Template:Demokratix Einmalquest" />
      <page pageid="1734" ns="10" title="Template:Demokratix Event Quest" />
      <page pageid="1736" ns="10" title="Template:Demokratix Wiederholquest" />
      <page pageid="5033" ns="10" title="Template:Dorfbewohner" />
      <page pageid="5142" ns="10" title="Template:Edifis Quest" />
      <page pageid="1711" ns="10" title="Template:Ep Ei Q" />
      <page pageid="1704" ns="10" title="Template:Ep Ev Q" />
    </pages>
  </query>
</api>