Information here is mostly on the various campaigns noted on the main page. Links are there and through tags in the right sidebar.
Also, video games (of which many have blurbs already listed here) lend themselves well to the “GM-Only Information” system.
Bunny Run (type-AA point-and-click game)
Dreadnought (type-B fan visual novel)
Lilith (type-A visual novel)
A Midsummer Night’s Fantasy (type-AAA visual novel)
Prospector (type-B RPG)
Siren the Amazon Exile (type-A fan RPG)
Ts (type-AA hidden object game)