I'm following up with DrewMelton.
The icon or title of a game isn't on the marketing side of things as much as it is simply illustrative work. The first image the player sees has to convey in a split second :
- what broad category of gameplay the game belongs to
- what the setting of the game is
This is not a place to trick the user into thinking that the game is great, but rather a way of conveying information extremely fast, in an entertaining fashion.
And this isn't only important as far as users are concerned, but also when you want to have publishers, editors and journalists pay some attention to your games. They are busy people, often receiving from dozens to hundreds of emails per day. So, you might only have 10 seconds of their attention to convince them that your work is worth taking a look at.
Lastly, PR and marketing are complementary, not opposite. If you don't market your game properly (yet ethically ), for example having a very ergonomic and appealing website to sell it from, it is unlikely that the press will make a miracle out of it.