The use and misuse of the term 'gameplay'

So why not be more specific?

"I like Mirror's Edge for the controls."
"I like this FPS for how satisfyingly intense the battles are."

..or something.

You make a very valid point, which nicely illustrates the difficulty of defining what, exactly, makes video gaming "fun" at all. On a superficial level, we all know that many games are good at least partly because of their great audiovisual presentation. But if one were to take a closer look at a lot of games with your specific problematization of "gameplay" in mind, I suspect one would find surprisingly many examples of well-received titles which, strictly speaking, aren't made such enjoyable experiences primarily by any of the characteristics which separates them from non-interactive entertainment, but rather by the very same elements one would find and appreciate in other forms of entertainment (in which they are obviously anything but "cosmetic"). And if so, what's the rationale for playing these games at all; rather than watching a good movie, reading a great book or listening to a fine album? And could these kinds of qualifications constitute a dangerous Trojan horse for rabid game bashers such as Roger Ebert to exploit? Just thinking out loud here...

To me gameplay has always referred to the system by which the player interacts with the game, which is how I try to refer to it when I write. I.E., an overarching term than encompasses things like controls, responsiveness, learning curve, etc. If a game has good gameplay, then it means interacting with the game is easy to learn. By that definition (which is again, just my own), gameplay is one side of the entire experience along with aesthetic aspects such as music, art style, writing, world/level design, etc. So in a nutshell, gameplay consists of the player's interaction with the game world, and aesthetics consists of the world with which the player is interacting.

However, I do agree that the term "gameplay" is used a little to liberally.

It's a really interesting point that it's sometimes hard to distinguish gameplay from graphical and audio non-gameplay elements. As you rightly say, there's a constant feedback between how a game looks and sounds and what the player does about it - a bit like style and content, which are basically indivisible (change one and you change the other). But still, everyone knows the difference.

In another sense isn't the definition of gameplay really easy? It's is what the player can do: move, jump, attack, defend, duck, climb, reload, pick up, discard, hit switch, and all the other things. It's also the rules (i.e. how those actions are constrained: you can move here, but not there) and what the opponents (AI or human) will do to stop you.

Whether or not those things are satisfying is where an appreciation of a game's aesthetics tends to blur with them, which may be why gameplay is sometimes used more loosely to mean the experience of playing a game rather than its basic mechanics.

You may be interested in this discussion of the artful interplay of gameplay, music, graphics, and other design elements.

http://versusclucluland.blogspot.com/2009/02/game-as-total-artwork.html

Certain aspects of the graphics should probably be considered part of the gameplay because the visuals are a form of feedback integral to player control. For example, camera movement has a dramatic influence on gameplay and the feel of the game. Likewise, the nature of the graphics enhance or detract from the gameplay. I'm not talking about how pretty the game looks. I'm talking about how the graphics influence the players ability to navigate and control the game.