To get it out of the way first, and so that there's no misconception here, the credit to the artist is in the credits at the end of the game. (and to prevent any future confusion, I've added it to the page itself)
Thank you so much for the detailed feedback. I really appreciate the thought and care you put into it.
I think your critique regarding repetition is absolutely valid; the loop of scavenging for a piece of debris and bringing it to the end of your bridge is monotonous. The line between relaxing and boring is a razor blade. There's nothing interesting that happens to the player between point A (finding debris) and B (placing it). In the back of my head, I had hoped that the ever increasing walk between pieces of debris to end of the bridge would force the player to consider the placement more carefully/most optimally, but admittedly, even that assumes the player would "dread" the long walks which is not "fun." I focused narrowly on the conceit that the player's expression was the bridge creation itself.
I understand what you're saying regarding the expression inherent in platformers vs top-down grid games. It's definitely something to consider going forward.
Again, this feedback has given me a lot to think about. I really appreciate it.