Hmm, I'd love to see a Game Dungeon on the older Elder Scrolls games. Mostly 'The Elder Scrolls' is directly tied to the Skyrim (/maybe/ Oblivion for some others) nowadays, that people often forget the old ones like Daggerfall or Arena.
Though the downside on that might be that Arena specificially is ridiculously big, with according to the Elder Scrolls wikia:
(Although that problem can be swiftly resolved with fast travel...)
I don't really know if this is a terrible idea or not, but I'm just putting my little idea here.