Over at DavidMullich.com I shared a couple of comments relating to his definitions on Games.
I agree with you. A Jigsaw puzzle is not a game, but could be made a game by adding a time limit (complete the puzzle in x amount of time). I believe you would say that this is an example of conflict (race vs the clock) while I would see it as a Puzzle made into a Game by the addition of the Play of Measurement (time being the measurable).
Some of the most popular games (The Sims, Sim City) have almost no conflict but are wonderful to play. Also Conway’s Game of Life is another example of how playful measurement makes it a Game with no conflict.