The speed affects the urgency of the boulder, and the size makes the boulder more threatening. Amount of boulders, space between rests, and time from last checkpoint or save can also affect the feeling of danger; these factors all assist in making the boulder have genuine weight on the player's actions and thus dangerous-ness. I balanced my safe zones by making them evenly spaced out while also making sure the player could not just sprint to end. I think my boulder hill is well balanced, although the final stretch is a bit of a tight squeeze. I improved sightlines by lowering most walls, but I added invisible extensions to stop the player from getting out of bounds. The Boulder hazard feels different because of how cramped the area is, even though the player technically has more space to move. The boulder is a challenge of timing in a cramped area with a constant threat, and the sweeper/narrow path is timing in a short section with nothing preventing forward movement. Destruction effects made the boulders' destructions feel more impactful, but not much besides that. I made my dust a bit more of a brown-ish colour, but I didn't make too many other modifications. Visual effects can help lead a player where to go, signal what is safe or important, or what is dangerous. I used the visual effects of light to let the player know where the safe-zones were, for example.