As the walls in the story grow higher and more difficult to climb, how do the characters change?

Hello. You did not enter the text to which this question refers, which makes it impossible to answer. However, I can help you by showing you concepts that will guide you in finding your answer.

Generally, within a narrative, the walls mean imprisonment or protection.

If the walls presented in your text are arresting the characters and depriving them of freedom, as these walls grow, the characters can change their behavior in a negative way becoming more stressed, paranoid, hopeless and melancholy, because that means their freedom is further and further away.

On the other hand, if these walls are protecting the characters from something, as these walls grow, the characters may behave more positively, as this prevents a possible threat from reaching them.