Here are the Lauri Puzzles that I got and Evie putting one together. You can make them easier by putting cardboard drawings under the puzzle and leaving the outline on the tray. If they are older or more experienced, you can remove the drawing. I wish I had bought some that were easier. Isaac gets quite frustrated but it is just right for Evie.
I love how colorful they are! I highly recommend these for the 4-6 year old set.