Charm
Course tutor Josh suggested that this is a key factor in making a game attractive to potential buyers, and also helps the player invest an certain amount of emotion even before the story has kicked in.
Josh gave the example of a clockwork robot winding down, which is a lot more charming than a timer in the corner of the screen. His particular example also illustrates the potential for overlap into other elements: the fact that the robot is winding down provides a fair amount of intrinsic story, and also affects the game mechanic as it slows down.(Josh also tied charm to nostalgia, which is something that needs proper investigation at a later stage.)
Experience vs. Enjoyment
Another theme which has cropped-up a few times is that of the player's experience -- the experience of playing the game (rather than prior experience).
The fact that the word has these two different meanings has caused me nightmares on this blog: it's difficult to use the word in an unambiguous manner while remaining succinct.
This got me looking for another word to use instead of 'experience'. After bashing my head against the thesaurus with little success I happened to think of 'enjoyment', which seemed -- initially -- to sum up what the player was getting from the situation.
However, after a bit of thinking around the situation it became apparent that the experience is not always synonymous with enjoyment. Indeed, they are different enough that it has now given me an important extra theme to consider!