A Simple WP_Query in a ShortCode/plugin

Hello Folks,
In a wordpress site i manage, i’m using an event query in many pages.
This query display a list of events (Im using event organiser).

My user would like to display this list in some specific pages.
It’s is why i would like to create a Short Code, showing this event list in a post page.
I created a plugin, and a shortcode, but it wont work.
The Foreach part does not show.
Could you tell me a to use a WP query in a plugin/function properly ?

Here is my query function (simplified).

<?php function wp_affiche_visites(){ ?>
<?php
	$term_slug = "visites-guidees-et-gustatives-de-la-goutte-dor";
    $events = new WP_Query(array(
          'numberposts'=>-1,
          'showpastevents'=>true,//Will be deprecated, but set it to true to play it safe.
		  'event-category'=>$term_slug
     ));
 if($events):
 return '<h1 class="page-title"> Visites guidées </h1>';
 return '<div>';

 foreach ($events as $event):
  return '<h3 style="margin:0; font-size:1em;"><a href="'.get_permalink($event->ID).'">'.get_the_title($event->ID).'</a></h3>';
 endforeach;
return '</div>';
 endif;

wp_reset_postdata();
}
add_shortcode('affiche_visites', 'wp_affiche_visites');
?>

The ShortCode [affiche_visites] just echoes “Visites guidées”.
Any ideas ?
Thanks you very much for any clues you could give me.