Ok...first I'll say that I feel like I'm butting in here.. that this collaborative effort was meant to be for non-professionals and that any contributions I might think I'm making are deservedly less welcome than were I just an amateur game designer.
First... there isn't a heckuva a big difference between an amateur and a pro... pretty much it boils down to that the pro has been paid for his ideas once or twice.
Second, my opinions are in no way any more apropos or accurate than any one else's. If I had that much of a lock on 'knowledge of gaming' I'd be fabulously wealthy by now.
...having thus said...
I think where you REALLY need to start is here: Why are you creating this collaborative design?
Is it in hopes of creating a product for market?
In hopes of creating a product that might be sold direct to consumers from sites such as this one?
Create a game that the designers and visitors here can download and create with their own equipment at home?
Just to have some fun and create a game that the designers will enjoy playing, with no regard to the ease with which it might be ported into either the market or home manufacture of created components?
All of the above answers are 'correct' insofar as they go... but anyone involved should know the hoped-for outcome, I'm thinking. I know it sounds corny, but I think your collaborative effort needs a 'mission statement'.
...just my two drachma.
XXOOCC
Thats VERY true... so we're kinda 'just for funnin' this one, which is ok too.
I have several full-blown prototypes in that category - games that will never see actual print for reasons that will become obvious once I list the titles:
Kill E.T.
The Castle of the Nameless Stains (an rpg adventure!)
Probing the depths of Uranus (although the gang out here is trying to convince me that that one is printable)
and a 'Harlequin-esque' dime novel called, "Vixen the Untold Story"
(about Vixen the only doe reindeer on Santa's team, and why she masqueraded for years as a buck).