Great game, looks easy at first, but is getting harder when most tiles are filled. I would surely give 5 stars, but, must subtract one star, Why? There is no 'save' function! After some hours of play I had more than 100,000 points and I wasn't finished yet. Went to bed, turn my iPhone off (as I do always as I go to sleep) and the next day, when I want to play on, I see empty squares with only two 2's! The same happend on my iPad.
A save function is essential here, even now when you can play on, using scrolls. I tend to download another version now, who has this save function.
