To add a new category to a page you can click the Category button at the bottom of the page and type in the name you'd like your category to be called.
A full list of existing categories can be found at Special:Categories.
Pages in category "Browse"
“ The factions are beings that fight in the Galaxian/Galaga series. Although there are more then...
“ The game companies are the guys who made the Galaxian/Galaga series.(Of course) We list them...