These are good points, HellishFiend -- that's what I've always done in the past, but I guess I worried that was getting a bit too concrete. A lot of other developers (even indies) tend to focus on the experience rather than the actual core things.
For instance, how would one market Half Life 2? Presuming it was an unknown thing, and not yet GOTY from that year, etc. On the one hand, you could say:
- 8 guns, including a physics gun.
- Several interactive allies that you can give basic orders to.
- Mysterious story spread out over 12 chapters.
- Several vehicle segments.
- Gunplay that feels tight, and graphics that are state of the art (for the time).
And that's all fine and well, but it wouldn't really sell me on Half Life 2. It just sounds like another entry in that genre, because most of those things are things that are, to greater or lesser extent, in every game in that genre. But instead, another way to go would be to try to sell the game based on the experience it provides, which seems to me a lot more to the point for that particular game:
- Waking up lost and alone in a dystopian society, aid the rebels in any way you can.
- Travel cross country on foot and in rickety buggies, past burned-out houses and through dangerous deserts.
- Pick your way carefully through zombie-infested tunnels and an entire town overrun by horrific creatures.
- Return with power to City 17, through intense squad firefights in the streets, in hopes of destroying the combine threat once and for all.
All of the above on that one hints at both story and game mechanics, as well as the sorts of environments you'll be exploring. It sounds like a singular fun time, standing or failing on its own merits, versus trying to pick bread A or bread B based on their respective nutritive qualities.
So... I'm not really sure. It may be that we need to do both. In our descriptive text, which it sounds like HellishFiend you would ignore, it might be that we need to sell the story/world/environment in the way that the second half life example attempts to. But then when it comes to the bullet points, we might need to stick to some more concrete facts, such as what your objectives are and how in general you go about achieving them -- what kind of game even is this, some one new wonders? -- etc.