Soon as I determine the framework to build mine on, it will be 90% text and 10% imagery. I think text is the way to go because it forces you to have the imagination to play it. Choosing the proper framework to begin with is essential, because once I start, it will have to stay that way or it will cost hours upon days to port it over something else. I need to use something with a past, a good developer community for reliance on security updates (as I don't want to handle that on top of a game), and a bright outlook for the future.
The 10% will be the layout and the character you build, but how you interact with the game will be mainly with text and reading.
Possibly 20% as I want to include a map too, and feel that Up/Down/Left/Right won't be as appealing as clicking on a square of a map to move to that position (and see your character overlay on the map). I had the Up/Down/Left/Right in my previous text-based game and nobody had issues with it, but times have changed a bit.