To illustrate the point, a live action tv show will live on a continuum from being extremely comical and light hearted to deadly serious, which is similar/related to but different from its level of realism. Most cartoons are right down one end of a levity scale with shows like 24 up the other end of such a seriousness scale.
However it turns out to be not quite so simple. Firstly there is how seriously the characters themselves are taking their activity and then another layer which is how seriously the show/novel/film depicts those endeavours. I have gone back and forth on this notion a few times, but the distinction seems to need some thought as The Clone Wars has serious characters in a quite light hearted cartoon and the same goes for the Avengers. That said, perhaps this important point is covered by other factors in a scale, thus making this idea of having a rating a touch easier.
I had the same debate over World Realism, Does the magic in Merlin make the show less more or less 'light' than Bones - maybe not - so any difference in lightness comes from other factors. Are Black Hawk Down and Avatar the same in terms of overall levity despite the more fantastic setting of Pandora?
So, I think we have worked out that the Visual Accuracy is significant, how cartoony the depiction is does have a real bearing on the 'lightness' of a piece of media. Bugs Bunny at one extreme and The Bourne Identity at the other (note that with more increments in the scale even these wouldn't be at the ends).
There are perhaps three things vying for attention still, Emotional Impact, how much feeling there is in what is expressed to us as the reader/viewer and how much is felt by the characters.; the foregrounding of the Morals/Message and lastly a simple measure of the Comedy vs Seriousness of the piece. While there are examples where all of these differentiate, if we make a call and allow the first two to be captured by the third then we end up with this grid version.
Yep, here is an attempt at a Media Leviticity Scale with two dimensions:
1 Extreme cartoonishnessI filled in one set of interpretations in the image and if I had to make a call now as to where Valley of the Winds would fall, I would pick D2 the same as the Clone Wars.
2 Human-like but clearly not real
3 Hybrid cartoony and realistic
4 Photographic but with visual liberties
5 Looks real (true to that world)
Note that 'fiction' here could be a novel, film, tv show, computer game, comic, cartoon, board game, play or other medium for the telling of some form of story/tale.