Before players decide to step into your magic circle and start having a good time, they have feelings. They might watch a video on YouTube, read an article about your game, or simply land on your store page and look at the trailers, screenshots, and descriptions.
All of this evokes emotions and feelings. Emotions are the first step of perception. That’s why when you start designing levels for a narrative-driven game (RPG, adventure, platformer, and so on), you need to think first about the emotional intensity curve over time. This way, you can properly estimate the moment-to-moment experience.
I recently used this approach for a personal exercise: creating a hypothetical level for The Last of Us.
You can see each step is associated with a specific dynamic I want the Player to experience during the level. This curve was the final one, but I worked on many iterations. You plan a curve, and then you iterate over time.