Thanks for the details Vinny. When I first saw your announcement I mistakenly took it for someone just interested in people making parts of a game for someone else, which was clearly my mistake.
This actually sounds like a cool contest, and I would do it. However, I can't for the next couple weeks.
To get better participation in contests, I think we need more announcement structure and better warning on when the contest would be. For example, announce the contest three-four weeks in advance, then get lots of comments and interest generated in it. Give some type of formal description of the contest, rules, judging, etc.... That will get more people interested in participating. As you get closer to the date of the contest, post reminders to keep visibility and interest up.
Just some thoughts. I would personally love to see more contest run for Construct. I'd even be willing to chip in some small prize money for the winner to encourage more participation!