We just played this for the first time and we're hooked.  My 5 year-old can play, but strategy is a little beyond her.  The 9 year-old completely gets it, and both my husband and I thought it was great.  I love that it's so simple and easy to pick up-- just a bunch of solid wooden tiles in a canvas bag.  Kind-of like an abstract version of Scrabble.  Lots of fun.  As simple or as complicated as you want it to be!