Vita: LittleBigPlanet, Gravity Rush, Tearaway.
Those games utilize the Vita hardware ( input methods ) in smart ways that can only work on the Vita.
Home consoles is where it gets tricky. We can not know for sure. Things like AI, FPS, the amount of enemies on the screen, the interactivity with the environments, the size of the areas. All can be considered "gameplay" because they have effects on your experience. Most compromises happen in those not so obvious elements.
How about Bloodborne extremely rich environments and destructible objects, or The Order solid 30fps ? Would you consider those to be "gameplay" ? I sure do.







