As we all know, dividing groups of people into two more or less opposites can be illuminating, certainly in the context of games. It can also be divisive of course, but I hope that will not prove to be the case here. Video gamers have made me realize that there are different ways to approach game playing as a part of your life. "Escapist Magazine" likes to talk about "the gamer lifestyle".
I've played games for more than 50 years but I have not seen it is a lifestyle, rather as a part of life. Perhaps because video games have been subject to so much criticism in the past, some videogame players think of the gamer lifestyle as a unique (and in some way superior) approach to the world and to life.
I'm not going to try to explicate that whole business, but I have seen that video gamers often approach game playing quite differently than I have. Simply put, they are Gamers while I am a Game Player, and I'll explain what I mean by those terms.
Gamers prefer game playing to almost any other activity. When they have "time to kill", they'll play games. On the other hand, Game Players treat game playing as one enjoyable activity amongst many. (And they may not think of games as "killing time" at all.) The Gamer frequently asks of a game, though often subconsciously, "is this a good way to kill time". The Game Player approaches a game with the question "is this a good way to spend my (valuable) time". These are generalizations of course, and there are going to be lots of people in the middle as there usually is with any division of the group into two parts.
Gamers play games because "that's what they do." Game Players play because they enjoy that activity amongst many others.
A Gamer will play virtually any game within broad categories, and could be said to have very wide-ranging tastes. For example, I've known Gamers who were willing to try almost any game "as long as it doesn't take more than an hour". Another example would be a person who will play almost any action videogame, or almost any role-playing game.
Game Players like to play games, but not just any game or not even "anything of a particular genre". They like specific games, or occasionally groups of games. A Game Player may just play one game or a specific category or specific favorite games.
If you ask a Gamer what his favorite game is, he will often be unable to say, or it will be the game he is currently playing. If you ask a Game Player what his favorite game is, he can probably say, and can probably tell you what all of his favorite games have been back to when he was very young, and this number may not have reached double figures even for someone who is a "senior citizen".
Tabletop Gamers are happy to participate in a group where people in turn choose which game to play and they all play it. Game Players rarely do that, unless they're with a group of similar-minded people with definite limits on the kinds of games they'll choose.
A sports analogy might help. The sports fan equivalent Gamer loves to watch sports, lots of different sports. He may be a season ticket holder if there is such an opportunity. The equivalent of a Game Player likes to watch certain sports, and may watch a lot of games, but doesn't feel a need to watch every game even of his favorite team. Life intervenes...
Gamers derive self-worth from being good at playing (video) games in general. If Game Players do, it's because they are extremely good at one game, or a few.
Gamers tend to treat games as a lifestyle or a job (think of all the people who talk about how much work it is to play MMOs). Game Players tend to treat games as a hobby.
So casual game players are much more likely to be Game Players than Gamers. And hard-core game players are much more likely to be Gamers than Game Players. Yet I do not equate hard-core with Gamers, or casual with Game Players. Someone who plays Magic: the Gathering incessantly, plays the game and tournaments, spends a a lot of money on cards, is a hard-core player but he's as likely to be a Game Player as a Gamer.
Are Gamers more passive in preferences and Game Players more active? I can make an argument either way. Game Players have favorite games. Game Players know what they want. Game Players are not just killing time, Gamers often are. Yet Gamers often have very strong opinions about games, and often are willing to have interminable discussions about the qualities of games, which traits are less common amongst Game Players.
Game Players focus their time, hence play certain games only (some play only one game, chess, D&D, Magic, Farmville, match-3 games, e.g.). Gamers tend to be less focused.
Gamers tend to dive into a game immediately. If it's a tabletop game, they may try to learn to play it while they're playing it, and many sets of contemporary tabletop game rules are written in "sequence of play" to make this more practical. Video games, of course, are ideal for diving in immediately. Tabletop Game Players like to study a game, like to read and even study the rules before playing.
Many game designers are primarily interested in making games for Gamers. This tends to mean that the designer need not be concerned about long-term replayability, because the Gamer is likely to soon go on to another game in any case. Those designing for Game Players may have a harder task, because game players tend to play their favorite games over and over again. A lot of published games don't hold up under the pressure of that criterion.