If you've completed all of the puzzles in one of the packs (including the Starter pack) you can reset them to be able to play them all again!

To do this, just tap and hold on the pack icon which says 'completed', and hold for about 5 seconds. It will ask you to confirm that you want to reset the puzzles.

Once you've done this you can replay them again, or have a friend or family member play them if you share a device.