You have 30 seconds - it's actually not that bad at all. Just run straight forward and up the tree. Go the way he does, right, straight, just belly slide and you beat him.

Note there's a blue coin on top of tree

You get a shine!

Tip from A spiro:
I think it is easier to beat him if you take the left road to the tree. I tried about 20 times on the right road (the same road he takes) and never won. The first time I took the left road, I won.

Super Mario Sunshine Walkthrough