Great, challenging nature puzzle.
924466
A very good, challenging puzzle.  Many irregular shaped pieces in the tree itself.  Lots of color changes.  It took me several days to complete.  I agree with the one reviewer that the pieces don't fit together as well as some Springbok puzzles.
2077587
Challenging puzzle that isn't the norm. It is large - very large, but a lot of fun and really great scene.
162757
This puzzle is definitely the hardest one we have done.  The birds were easy but the blue and white background was very, very challenging.  We had to develop more advanced puzzling technique to deal with the unpatterned background - but after several days we achieved the goal of not being defeated by a jigsaw puzzle.  We don't plan to do another as hard.  Again, Galison has produced another well-crafted puzzle with pieces that fit perfectly and - no missing pieces.
2140155
This puzzle is challenging, but fun! The colors are similar and the lines aren't clean so it can be hard to distinguish where pieces go. If you're up for a challenge, this is great one!
752841
We (spouse, daughter and I) loved doing this puzzle. First, it's really gorgeous, and it's fairly challenging. There are many aspects of the puzzle to enjoy, even the shapes of the pieces themselves. We discovered that the top edge of the puzzle is not even, and it bursts with little shapes.. How fun to do a jigsaw puzzle that played around with the that "find the edge piece" strategy. Really creative.
3509249
Puzzle arrived prior to delivery date and no damage to packaging. Puzzle contains crisp colors with just the right amount of challenge.
3768610
Beautiful puzzle!  Intriguing subject and colors.  I like that there were so many different distinct aspects to sort out.  That made for a fun puzzle to put together.  Excellent quality with a substantial feel to the pieces.  I highly recommend it.  To me it was of average difficulty.  I enjoyed it very much.
4125956
I really like this puzzle.  My 3 year old grandson can put it together with help.  It has really sturdy pieces that go together well.
1162079
A challenging yet beautiful puzzle that was well made in the USA.
4372126
Great puzzle, definitely challenging but not so much that you want to give up.
2717353
I have found this to be a good challenging puzzle.  With it being a mosaic, it adds an extra level of difficulty but not so difficult that you will have trouble completing it.
3911419
This puzzle was a lot of fun to do.  The pieces for big and differently shaped. That made is easier for us to do.  The color are bright and very much like the cover on the box.  We love White Mountain Puzzles.
2782160
We loved this puzzle.  Just a little challenging with all the white and green, but I completed it with my 5 year old* in a week. (We spent maybe an hour or more a day on it.) *He is pretty awesome at puzzles. ;)
4467779
Fun puzzle and the age of 8+ years is accurate. My nephew enjoyed the puzzle and it generates a nice conversation about our oceans, wildlife, and science.
222424
I really enjoyed this puzzle. It was a good challenge with 500 pieces. The quality of the pieces was good and the pictures in the end turned out really nice. I would recommend this one for nice long evening.
1108656
My wife and I took 2 weeks to finish this puzzle. We would work on it whenever we happened to pass it on our dining room table. Because of the multitude of colors and objects (birds and flowers), it is quite difficult; but that's what we want in an adult puzzle: a good challenge. The puzzle is very well made. The pieces are cut precisely, and they do not fall apart. I recommend this puzzle very highly for adults and children 12 and older.
3805466
Ravensburger makes some of the best puzzles and this one does not disappoint.  It is 1000 pieces and very difficult but the reward is worth all the hard work.  The pieces are all cut cleanly with very few still connected.  They are also each unique so you can easily tell if a piece "fits".  I recently helped with a cheap child's puzzle where all the pieces were identical.  Ugh!  That was not the case with this puzzle.  The picture has a lot of objects in it that are the same or similar colors which adds to the degree of difficulty.  It took several days for two adults to put this together and the finished product is very pretty.  We downloaded the app to try out the interactive part.  The app is VERY large and took quite a while to download.  However, it was fun to play with and could be great if you have small children.  It shows a fish and then you point to the fish on the puzzle with your finger.  One complaint about this puzzle - the picture on the front of the box is blocked by the advertisement about the app.  This made that corner of the puzzle even more difficult than it already was.