Perhaps an appropriate engine could be made available as a "default" engine for the competitions. This would allow people to use their own engine if they wish, but helps out new starters by giving them something to work with.

Another thing that would be very useful, especially for the short competitions, is a content pack. The pack could include some models/textures/sounds/etc for use in the competition. eg: a fantasy competition may have a warrior and mage, a few trees and grass textures. For some competitions the requirement may be to use only the supplied content and focus on gameplay.

Just a (very sleep deprived) thought.