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="Smia_800x495.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="185" ns="6" title="Fil:Bamse brakar.spx" />
      <page pageid="186" ns="6" title="Fil:De tre bukkene bruse.spx" />
      <page pageid="187" ns="6" title="Fil:De tre bukkene bruse fx.spx" />
      <page pageid="189" ns="6" title="Fil:Haakon meland eriksen.png" />
      <page pageid="190" ns="6" title="Fil:Hanen gauken og arhanen.spx" />
      <page pageid="191" ns="6" title="Fil:Hanen og hona.spx" />
      <page pageid="192" ns="6" title="Fil:Haren som hadde vart gift.spx" />
      <page pageid="193" ns="6" title="Fil:Hver synes best om sine barn.spx" />
      <page pageid="194" ns="6" title="Fil:Kjaresten i skogen.spx" />
      <page pageid="197" ns="6" title="Fil:Pannekaken.spx" />
    </pages>
  </query>
</api>