Defining "Hard Core" and "Casual"?

In class we spent some time trying to differentiate between “Hard Core” and “Casual” video game players.  This kind of endeavor usually results in a fairly good list, but it’s likely more can be added to it.  I’ve decided to post it here to see what people think.

Hard core and casual video gamers
Some characteristics that might help define the two types.

HardCore are likely to play almost every day.
Casual play now and again or frequently, varies a lot.  
But the HardCore will spend a lot more time per week playing, than the Casual.

Casual play in "short sessions" (think “Bejewled”).
Often, the game is over quickly, but you play the game many times over the course of weeks or months.

HardCore play in "long sessions" (several hours).
Usually the game takes a long time to finish, and you may play it only once,
    because you've figured out all the puzzles,
OR    because now you know the story.

Casual games are often of the "you don't have to concentrate constantly on the game" type.
HardCore games are often "you have to concentrate constantly or you'll get dead".  Or if you don’t need to concentrate constantly, you still need to think a lot or you’ll lose.  (Think Civilization.)

HardCore probably don't have a "favorite game" over a long period (years)--because they "finish" games and are done with them.
Casual may have a favorite game over a long period, but the “cult of the new” is strong today, so they may continue to move on to new games frequently.

HardCore are usually competitive (or pseudo-competitive, e.g. when comparing scores or time taken to complete a game for single-player games).  They see the game as an adversary and want to “beat it”.
Casual tend not to be very competitive.

“Achievements” are of interest to HardCore, rarely to Casual players.  

HardCore are often more concerned with “the destination” than with “the journey”, but this can extend to Casual as well.    Casual tend to want to play something that they can enjoy while playing, rather than enjoy only when they’ve finished (“beat the game”).  If a game is “too much like work”, they’ll stop playing it; the HardCore often continue to play in this situation in order to reach the goal of beating the game.

HardCore are rarely playing “to relax”.  Casual often play a short session “to relax”, then go back to the real world.

I don’t know which of these video gamer types is more likely to play non-electronic games.  The popular board and card games of today tend to be “Casual” more than “HardCore” experiences.  (Forget traditional games, I’m talking about hobby games such as Settlers of Catan, Dominion, Carcassonne, and so forth.)