If it can be any form of material, mousemats/t-shirts/etc that kind of thing will work well.
If it has to be more civilised, maybe some HQ posters from great screenshots of KU would work.
It could include some s/n for the game, but it depends on what the competition is. If the competition for example uses KU then that would make no sense.
You could always put your older games in the prices, such as Saira and NightSky.
If the press is about a magazine, it could be either a subscription to that magazine or some issues.
There are more ideas, but this is what I can come up with this soon.