In this level, it's important to note that the marbles can greatly screw up your plans.
In some areas, you can jump over them, some not. In every case, you can blow the floor out from under you, to send a marble on a detour, which you can hop over.
If the marbles are really a problem, make note of the marble trap spots in which you can permanently trap some marbles (yes, multiple at once!).
Off the top of my head, here's an initial route idea:
I'll need to look closer though to see if I can come up with something better. I dislike the repeat travel.
It's important to note in this route map, the initial stages of it is around the heavy marble trapping areas. If they need trapping, probably best to do so early on.
Edit:
Another route:
Edit:
Our level editor image shows a full fuel tank on start, so ignore my routes.