I honestly had a lot of trouble getting through games like Sonic 2. If you were to play Sonic 2 end-to-end its probably 3-4 hours. But the reality is getting through it all was challenging. It wasn't 40 hours of puzzles, nono.

This is not to say that that is the right way to make a game, but it was to say that playing it was a challenge for young me. Today the only games I find challenging is PvP games, but often times I don't want the other parts of the challenge like the actual people part. This is why some games like Demon's Souls (the first time I ever saw a castle in the distance that I could literally walk up to and smash through, was an awe moment) still stick in my mind.