Just challenging enough to keep you engaged without being frustrating. Simple to learn, hard to master, monthly puzzles for something a bit different, nice graphics. Just a fun casual puzzle that you can keep coming back to over and over when you need a break.
I'm not normally a fan of these types of games, but I happened to pick this one up and I'm so glad I did. I can't seem to put my finger on it, but Dorf Romantik is incredibly addicting. It's not the type of game you'll waste hours and hours playing in one sitting, but it's nice to be able to pick up whenever you have a chance. Very laidback but incredibly challenging to master.