Prompt 2: Describe the challenge of the game as if the designer was working to thwart you.
The game fitness challenge wants the player to lose eventually, because it's a never ending game. The game is basically controlling a running boy and the goal is to run as long as you can. The game will try to make the player lose from two directions: the obstacle from top and the puddle from below. The player can jump or roll to prevent dying from the obstacles. The game anticipated that the player might want to only press jump to escape dying from the puddle, but if the player did only pressed the up button, the timing must be absolutely right to not die. In order to give the myself a longer window to react, I must add right arrow keys to let the character jump longer. This is also part of how the game wants the players to lose, but learn from losing.
The game doesn't really have enemies, only the obstacles that makes the victory(or living longer and earn more points) difficult. An interesting point is, after the player gain over 100 points from living, the game becomes harder, and the rise of difficulty comes not only from the bigger obstacles, but also the running speed of the character. The speed is faster so it shortens the reaction window of the players. The colors and music also changes to alert the player when this change in difficulty happens.