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>
    <allimages gaicontinue="011_script_ostacolo.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="49" ns="6" title="File:000 nuovo sprite da file.png" />
      <page pageid="50" ns="6" title="File:001 script movimento mostro.png" />
      <page pageid="51" ns="6" title="File:003 crea e modifica sfondo.png" />
      <page pageid="52" ns="6" title="File:004 sfondo game over.png" />
      <page pageid="53" ns="6" title="File:005 creazione nuova variabile.png" />
      <page pageid="54" ns="6" title="File:006 script stage.png" />
      <page pageid="56" ns="6" title="File:007 stop nascondi.png" />
      <page pageid="57" ns="6" title="File:008 script per sprite palla.png" />
      <page pageid="58" ns="6" title="File:009 mostro script versione evoluta.png" />
      <page pageid="59" ns="6" title="File:010 script palla versione evoluta.png" />
    </pages>
  </query>
</api>