diff --git a/PROPOSAL_20210747.md b/PROPOSAL_20210747.md
index 1e856ac..a71c424 100644
--- a/PROPOSAL_20210747.md
+++ b/PROPOSAL_20210747.md
@@ -87,4 +87,4 @@ class World {
 
 ### 4. Expected Challenges
 <!-- What do you expect to be the main challenges? What features taught in class do you expect to use in your implementation? -->
-The expected main challenges from this project is how to make the cat rendered dynamically (as walking) when it moves. I will use the `p5.js` library to make the rendering, so I think keeping a local state of whether the Cat is moving or not and render the visual accordingly might work.
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+The expected main challenge is implementing dynamic cat animation when it moves, so to make it looks like the cat is running. I plan to keep track of the cat's movement state globally to show if during the rendering stage the cat should be in running animation. I also want to implement scrolling levels where the window follows the cat's movement, but I'm still figuring out how to track the cat's position relative to the viewport for camera movement.
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