i had an item like this in a rss feed, and i wanted to grab the enclosure url, took me a while to figure this out for some reason even though the solution is quite simple. 

PHP

<item>
<title>title</title>
<link>https://kruxor.com/</link>
<dc:creator>
<![CDATA[ KRUXOR ]]>
</dc:creator>
<enclosure url="https://kruxor.com/logo.jpg" type="image/jpeg"/>
<category>
<![CDATA[ Cat ]]>
</category>
<description>
<![CDATA[ Text ]]>
</description>
<content:encoded>
<![CDATA[ <p>Long Text</p> ]]>
</content:encoded>
<pubDate>Thu, 29 Sep 2022 03:10:07 GMT</pubDate>
<guid isPermaLink="true">https://kruxor.com/</guid>
</item>

Just use get_enclosure and then get_link rather than trying to access the object returned by the get_enclosure function. 

$game_news->image = $item->get_enclosure()->get_link();

..