On the game’s main menu, you will see a mosaic icon at the top of the screen. Tap this to open the mosaic and play any puzzles you've unlocked.

During the event, play or replay any puzzles to earn stars and level up. Each time you level up, you will receive a reward, such as unlocking puzzles in the mosaic.

The puzzles in the event pack can only be unlocked through these rewards while the event is active.