Growth's rules are simple but very well designed: the game is relaxing without being trivial.
The interface is fluid and pleasant.
The only drawback, at least for me, is the final hexagon: it is a quite annoying maze that makes the game less enjoyable. You have to stockpile lots of pieces (especially of some types) in advance and then hope they will last long enough.
I think the game could be made better by somewhat relaxing that maze and making its pattern a bit more varied from a play to the next, same as the rest of the map.