The game is never "over" technically because you can keep playing with your villagers as long as you want. As far as challenges that LDW has set up, once you do all 12 puzzles that is the end of puzzles. But you can always start over, try a different strategy, up the difficulty level or speed, and have the fun all over again! It's up to you how you want to play, but VS is open ended in that you can continue to support your village even when the puzzles are done.
And as an added comment a lot of us are trying to encourage Arthur and the team to do add-ons in an upgrade so we have more puzzles or areas to explore
