Well. your blog is your content. So write better posts that will encourage people to subscribe to read what you've got to say next. Screenshots, youtube video embeds, and some quick one line blurbs are not gonna keep people subscribing. Especially if some of the content was debuted months and months ago.

Majority of gamers stay up-to-date with gaming-related topics, so they'll have already seen old content. Don't go back in time to get content. Stick with present and future.