The biggest problem I have found in the game play is that once you have Fishing (Farming Level 3) the game is effectively over.
At that point the only critical resource in the game (food) becomes, essentially, unlimited. At this point the game only requires human intervention to solve the few remaining puzzles.
Those puzzles, for the most part, serve no purpose. The early ones, building a hut, clearing the blockage, etc, all lead to something else. The boulder, the fruit of life, and the treasure are dead ends.
I enjoyed playing the game immensely, but once I reached that point it was a tremendous let down.