oh this is just the debug menu in case you run into an error (which I have probably solved at this point, so you shouldn't run into it anymore, anyway). If you completed all endings, then you don't need to worry about it. No extra content to be found there :)
How do i unlock that hidden code on the wall closer to fios room? i have alredy finished all the 8 endings and i have no clue about this one.