SELECT
  rev_user_text,
  rev_timestamp
FROM revision
JOIN (SELECT DISTINCT
        SUBSTRING_INDEX(page_title, '/', 1) AS page_title
      FROM page
      JOIN categorylinks
      ON cl_from = page_id
      WHERE cl_to = 'WikiProject_Video_games_members'
      AND page_namespace = 2) AS cltmp
ON REPLACE(cltmp.page_title, '_', ' ') = rev_user_text
WHERE rev_timestamp = (SELECT
                         MAX(rev_timestamp)
                       FROM revision
                       WHERE rev_user_text = REPLACE(cltmp.page_title, '_', ' '));