Hiya Meredith, I really enjoy the background image for your menu scene. It makes me feel like I'm about to venture down the footpath and triggers the desire to put out a hand and touch the flowers as I walk. It's happy and engages my attention well. I love the colour green, so I appreciate your choices for your buttons and header panel.
I agree with Lucy in maybe changing your text colour for your instructions; however, I do get the feeling that maybe they were supposed to sit underneath the game title, sharing the green panel. If that were the case, then the white text would have been fine.
I enjoyed interacting with your rolling Echidna, too. Such a great demonstration of your use of Unity's ProBuilder! It's great that your character's body changes direction as you move it around, and the chime on collection is a nice touch. My only feedback for your game scene would be to possibly add some kind of game barrier to stop the Echidna from falling into the abyss...which I did a couple of times.