Adventure games in the 1990s were full of abstract puzzles that provided a binary mental challenge—you either got the solution, or you were left to struggle on your own. Players would often end up scouring the game world, scanning every single screen, and trying every possible item combination. Nowadays, a game with that degree of friction will likely frustrate the player to a point of quitting. When possible, avoid mandatory puzzles with binary win/lose conditions, or make sure to include a passive or active hint system.
If you are looking for inspiration, try the games in the Professor Layton series, where hundreds of clever (and often very difficult) puzzles are paired with a well-implemented ...
