The design is not up for discussion, so I'll refrain from commenting on that, but I would like to point out that this:
The screen-bound spaces are very simple.
is not correct. Whether game code is complex or not depends on what it is modeling and its performance constraints, and has nothing to do with how it is presented. Certain aspects of presentation can put certain requirements on parts of the game code, but whether they are more complex or not than something with a different type of presentation is often an entirely independent question.
I can personally guarantee you that our game code even as it pertains to the notion of individual screens
will be vastly more complicated than most
games that use scrolling.