A nice simple puzzle game without a lot of pressure to buy things in-game with real money. Some pop-up ads, but they're the kind that are easy to close. The interface is a little off, you don't really have an inventory when you get some items, you have to open the shop to find them there to place them. I could have sworn there was an option to upgrade to adfree for about $3.50 but I can't find it now. These are all minor complaints, though, and I do really like the game and would recommend it.