1. An inspired concept
2. Larger than life characters
3. A high-stake story
4. A deeply felt theme
5. A vivid setting
Check, check, check, check, check, check. (I hope, hope, hope, hope, hope and hope.)
(I lifted this from an agent interview at 2009 SCBWI LA blog) She talked about novels but I think this can apply to pbs as well.) I am going to add an original presentation.
And the stakes only have to be high and of uttermost importance to the protagonist.
There can be more than one theme. I say themes that we all can relate to and have experienced.
'Inspired concept' is key. Being inspired in writing and illustration is critical. No 'so what' allowed.