You can view recent changes per category, but you need to type in the URL to find it!
For the gaming category, you would visit Special:RecentChangesLinked/Category:Video games by typing the URL http://answers.wikia.com/wiki/Special:RecentChangesLinked/Category:Video_games
You can change "Video games" to any category name you are interested in.
Once you're on the special recent changes page, you can subscribe to an RSS feed of that category.
For example, the gaming one is at http://answers.wikia.com/index.php?title=Special:RecentChangesLinked&feed=rss&target=Category%3AVideo_games