Template suggestions not recognized
You try this code.

 function youthemename_preprocess_node(&amp;$variables) {
 $node = $variables['node'];
    if($node-&gt;type == 'project'){
      // Determine project type based on a term field.
      $project_type = $node-&gt;field_genre['und'][0]['tid'];

      switch($project_type){
        case 4:
          $variables['theme_hook_suggestions'][] = 'node__project_pcgame';
          break;
        default:
          $variables['theme_hook_suggestions'][] = 'node__project_movie';
      }
    }   
}


You file name should be node--project_pcgame.tpl.php and node--project_movie.tpl.php.
Clear performance cache, it should call hook_theme_registry_alter(&amp;$theme_registry).