I really dislike any attempt to draw a distinction between “casual” (a dismissive term) games from “core” games. This is pure gate keeping behavior; an attempt to diminish some games (and therefore their players) as being less real than others.
If you wish to separate “core” gamers, do it by device or by category, since that is much clearer and carries less of a value judgement.
If you wish to separate “core” gamers, do it by device or by category, since that is much clearer and carries less of a value judgement.