Not sure if I know exactly what you are trying to do
– Are you talking about just a homepage on all sites being used having the ability to change?
– But these sites would have similar areas, game guides etc..?
– Or are you looking for a way to amend multiple pages at once
Many site building programmes allowing you to generate one page, your homepage for example and if you are looking to change content across a number of sites, you would build multiple homepages from the one template to be used with different URL’s and once you amended one they would all update.
Alternatively I have found building sites using SSI tags really helpful as you essentially have the site build in slices which connect like a jigsaw when uploaded.
Let me know if you need any more detail