In the dark ages of video games, where game play was a relatively new concept to the programmers who had control of the game play and had very little creativity of their own and never really thought that the same challenges and puzzles would get boring. This lack of creativity quickly spawned a job for someone who actually knew how to interact with people (sort of) and give them something enjoyable about a game. As the word GAME suggests it’s something to do for fun and being killed by the same flashing monster because the difficulty curve suddenly shoots higher than Hubble space telescope would often lead to gamers being disgruntled and moving on to the next headache inducing game that came along and never return to it.
Game play is vital in making a successful game that will sell and not be slated in every review article under the sun. Also players have become more sophisticated and want more for their money. If the game designers trap a player at a point in the game and make it impossible to get past and causes the gamer to want to throw their controller and punch a hole in the wall it ruins the fun element of a game and they have failed. Of course you don’t want to go to far the other way and hold the players hand through a game to the point where they can press the win button on the controller to complete the game such as the recent game WET where the boss is just a couple of quick time events and slow repetitive button pressing until you see a small cut scene where dies in a sort of disatisfying pathetic way.
Ultimately what I’m getting at is that good game design is all about balance. Most early games went for the steady climb in difficulty through levels, but today the advancements in games has lead to a more progressive up and down difficulty throughout each level, unless of course we mention the lovely Psychonauts where the difficulty goes up and down all over the place and matches its wacky psychedelic look. There is no perfect formula for creating a goldilocks game where its not too hard or too difficult as some players are smarter or quicker than others making the experience completely different for everyone.