If you were skilled enough, i'd love to see an article talking about kaizo levels and how to actually do some of the tricks they do. Talking throwing a shell at a wall/pipe, and then bouncing off it to gain extra height.
As for going old-school nintendo magazine, level layouts of difficult games, hidden easter eggs, maybe delving into
Larry Bundy Jr stuff and extracting tidbits to use. Some games have source code included in the roms or comments which could be hilariously funny.
8Bit Guy talks graphics for NES so going into some of the technical aspects of the NES could be interesting.
Really bad mistranslations or interesting games/gems that are generally missed.