https://mailchi.mp/841f564080b9/nggnewslettergiveaway -sign up for their newsletter on that page to get a Free copy of Pirates: All Aboard today only. Once you own that game(or any No Gravity game), you’ll qualify to get a Free game every day until December 20.
The free games will be listed daily at this link starting on Monday, December 11, but you have to do it every day or you won’t qualify for the future free games. The free pirates games doesn’t seem to come immediately, so hopefully they send the code before the promotion starts on Monday.