The selection of featured jams is an opaque and seemingly random process. Over our past 20 jams we've noticed no pattern at all (some were featured, some were not), and itch refuses to make any clarification on the process.
If you want to help get the jam featured, the best thing to do is tweet @itchio to let them know you want the jam featured. I don't suggest bothering support, as they have their hands full with a number of other important issues for the site, and I've already submitted a request.
