We've had two of these puzzle events so far and both were pretty poorly received by all the feedback I see. I missed the first girl and got Hari with just 3 seconds left on the event. But this actually gave me an idea on how to redesign it to be more fun. Here's my suggestion:
Extend the event to 7 days. It's too easy to get busy and miss the first day or two and be incredibly far behind.
Here's the big one: Change how the puzzle and timer work overall. Keep the 10 stages for the girl, but eliminate the current limit on moves. Instead, switch the event to a timed puzzle - keep the same basic design, but you press a "Start" button and then you have X minutes to put the pieces into place. Perhaps there is also a limit on moves, as well, to keep it exciting. So a 12-piece puzzle might give you 2 minutes and 24 moves. The final stage with 25 pieces could give you just 3:30 or 4 minutes, and just 40 moves. This would need to be tested to find the right balance between challenge and frustration. But when the time is up or you solve the puzzle, then there's a two or three hour lockout to try again. This is the timed element - you have a limited number of attempts per day due to this. BUT, you can rest the timer to try again right away by spending Ryos. That's how you keep it monetized without feeling excessive.
Change the pictures from the dull, generic current crystal, flower, and phone to teaser images of the girl in the event. Use a still of her upper body or something from her level 1, 4, and 7 poses to tease us and get us excited about unlocking her!
So that's my thoughts. The puzzle is pretty dull right now, but because of my poor time management, I went into level 9 this morning with just 7 minutes left on the event. Having to solve those last two stages with a short time limit made it WAY more interesting and exciting. So, I thought I'd share that perspective and toss it out there for others to consider.