Let's say I extracted some assets from a closed source game.
Am I allowed to publish information (something like a list of filenames, sizes, duration, dimensions...) about those assets?
Facts are not protected by copyrights but you should check if there aren't other local laws that apply where you live.
Copyright does not protect facts, ideas, systems, or methods of operation, although it may protect the way these things are expressed.
Many countries have international treaties to follow the same general copyright law (See Berne Convention). But not all follow the USA's copyright term extension act (A.K.A. Mickey Mouse Protection Act) that were changed after the initial agreement and every country will have variation in their interpretation of what constitute fair use.