I highly recommend
This game is super fun and addictive. A few took a while to complete, and others are even harder to perfect. By far the hardest puzzle game I’ve played on my iPhone. I can’t beat level 25 :(. But I love that there are no ads, I actually have to think, and you don’t have to beat a level to play the next one. You can play any of the first 30 levels once you download it!