This was great fun, starting with the irregular edge, anything with a straight edge, and their are many, can't be a border piece. In general each group of 4 pieces has a small or whimsical piece in their center. All the squirrels (about 10), dozens of birds and maple leaves everywhere make this puzzle a challenge. I thought starting with the rocks might be easy, not so much... My time ended up at 155 pieces in 150 minutes or about one piece per minute. I think that will be a respectable time for one person and so much fun.
My friend friend who NEVER looks at the box is taking this one home with her. I had to use the box to place each branch, each squirrel and every bird. She generally does puzzles in the same time I do with out looking at the box but this time I think I have the advantage.
So hard as to not be a tedious bore, still possible to finish in one day or one sitting. This puzzle is rated "Really Hard" by Artifact, and I think that is an accurate rating without the epic effort required for a 500 or 1000 piece "Really Hard" jigsaw puzzle.