Check out the Quest for Glory games. They are open world, the puzzles can be solved in any order, and each puzzle has three possible solutions (roughly correspo

Check out the Quest for Glory games. They are open world, the puzzles can be solved in any order, and each puzzle has three possible solutions (roughly corresponding to fighter/wizard/thief methods of problem solving). Also, many of the subquests are optional and you can beat the game after solving only about 50% of the puzzles. There was recently a free spiritual successor called Heroine's Quest which was pretty enjoyable as well.