This might be better off in the Miscellaneous Forum - mods move if necessary.
Work for Free - Really? This is not to say that some great things have not been accomplished by friends pitching in - but getting the garage painted and getting a game designed for sale are two different things.
At 61 - I have been sewing since I was nine years old; I sewed and designed clothing and costumes in both professional and non-professional theatre. Any 'home sewer/craftsperson' will tell you - people think that 'since you sew' - that you can make them a shirt for less than Wal*Mart is paying slave labor to crank out 1,000s of shirts on a rack. You want ONE shirt? That is custom work - expect it to cost you twice as much or MORE than 'off the rack'. Time is money.
Once someone wanted me to 'make them a vest' - I never did. Much later I related to a relative of theirs that the conversation never mentioned paying for me - or for the materials! Had they asked me where to buy cheap fabric & notions and bought all the supplies I 'might' have made the vest for them. Time is money.
I worked for a theatre that wanted to do a musical (musicals are expensive to produce) - it could not use a 'piano player' to bang out the score - it needed a 4-piece bluegrass combo - and they wanted to find 'Free Musicians' to play the show! People who make music for a living have families and bills to pay, too - so no free bluegrass musicians were to be found.
Have I given my time and talents away? Yes - to charitable institutions and events where no participant was getting paid and all proceeds went to a charitable cause.
Designing a game to sell to the public with expectations to make a profit is not a charitable cause. Offer hopeful designers and production crew something, even if it is the barest minimum you can scrape together. Offer them a % of future sales - and expect them to want you to sign a contract. Unless you have the budget to pay an artist as 'Work for Hire' where they get a one-time payment and no residuals - you cannot expect anyone to give away their expertise and time - Time Is Money.