Hi DarkWaitress and welcome to The Hollow. We're glad you finally made it over and hope you'll jump in whenever you're ready. Hope to see you around, btw cool avatar. :)
Not all of the challenges win free games, in fact most don't. The first post in the challenge thread gives the rules and states whether you can win a game or not. If you do win a challenge with a free game there is no 'catch'. You will be given the coupon code and you simply redeem it at PF.
As far as the challenges go, most of them are for fun, the two that are running now, The Fashion Dash Challenge, and the Passport to Perfume challenge are both just for fun, and bragging rights!
Occasionally the Challenge will have a game as a prize, the challenge thread will ALWAYS say if it is a FUN challenge, which means no real prize, or that the winner will receive a free game. If there are any questions about a specific challenge, and the challenge thread doesn't answer your question, just ask, and someone here will usually be more than happy to answer it for you!
I hope I helped, instead of making it more confusing for you!
