Zynga launches it's second Slingo cross promotion in Hidden Chronicles...
Clicking the Slingo 'PLAY NOW' Icon on the right side of the game screen to launch the game
Once you are in you just need to get every number on 10 boards.
Those of you who have played Zynga Slingo before this should be very easy to accomplish and you've might already have 10 Full Cards... It completed instantly for me.