3. The main differentiator of the game, the characters one can interact with on the side - and how they can react.
I really like that, after giving one girl a board, one other NPC mentioned it. That is a detail I wish more games would include. In that regard I already consider this simple proof-of-concept of yours above Bethesda and BioWare; both of those companies have sterile NPC's generally oblivious.
4. The optimistic nature of the dialogue and plot and side-quests, without blithe dismissals or other dystopic extremes, and without getting mushy. That's really rare in entertainment today, especially in computer games where almost every title out there has "enemies" and characters being insensitive or mean.
The simple option of giving that little girl a new board and reading what she has to say warms my heart, and embodies this ideally.
That aforementioned detail of the bystander commending us for choosing to return that girl's board, affirms this experience as well as being its own welcome dose of optimism.
Admittedly this is the last item on my list, for now; however, it is not by any means the least.