Not too sure of it myself yet, but in general I feel we need to look for concepts based heavily around community interaction and social/economic structures. The main draw of such games is a complex ever-changing microcosm the player can immerse themselves in, a nested world that imitates reality.

Blockchain works well for this because it is already designed to make digital things 'real', meaning a world stored within it would essentially become a real world. Meaning every action a player takes is also real, which who knows what insane implications this might have on how the collective output of those actions shapes the landscape of a game's community.

Either way, a game like Fallen London would be the perfect fit at this stage of blockchain development. Who knows where we might go from there. http://fallenlondon.storynexus.com/