A really interesting mechanic here! Totally understand the overscoping problem but hope you come back to this for more levels because there's definitely room for more puzzles. I was also amused that I could die in the game over screen :)
Is this the controller you were using? https://assetstore.unity.com/packages/tools/physics/kinematic-character-controll... Movement was very smooth, so I'm genuinely interested for future projects.
Yes, I did allow for death in the GameOver screen because I did not have time to disable it in that screen. I submitted with 14 seconds to spare. Your comment definitely brought a smile to me. Yes, that Kinematic Controller from the asset store is what I used. It use to be a $50 asset then Unity bought it out, they made it free. It is a very good controller, It is meant for 3d but I just froze the z axis and restricted movement of all my 3d rigidbodies to the x, y plane and froze rotation in everything but the z axis.
