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>
    <allfileusages gafcontinue="BOMBER.png|35" />
  </query-continue>
  <query>
    <pages>
      <page pageid="32" ns="0" title="Ракеты" />
      <page pageid="34" ns="0" title="Конструкции" />
      <page pageid="253" ns="0" title="Офицеры" />
      <page pageid="255" ns="0" title="Артефакты" />
      <page pageid="479" ns="0" title="Базука" />
      <page pageid="509" ns="0" title="Барьер" />
      <page pageid="512" ns="0" title="Чёрная дыра" />
    </pages>
  </query>
</api>