I have played this a lot! The Star Challenges are what appeal to me the most--I have 1026 stars currently. For some of the themes I have trouble distinguishing between whatever two colors they choose to swap for red and black; usually I can fix that by playing with the Android color-blindness compensation settings. I think I have all the achievements too, except for the Daily Challenge ones.
The expert level Spider and Freecell games can be real stumpers. Also harder Klondike can be difficult to strategize. More then once I have asked Anna to figure out a Klondike deal for me and she beats it on the first try.
It is fun to play on PC occasionally too, very nice that all my progress syncs.