Any1-3

Optimal

This level features some precise Marbles movement, including minimizing flapping to preserve speed.

All written times will use the in-game timer, NOT the YouTube timestamps.

At 0:08 it is helpful to spin-dash again to regain top speed, since some is likely lost to flapping in this section. At 0:10, an extra midair spin-dash or two is helpful for getting under the bees without falling in the water or needing to flap a lot.
If you're having trouble avoiding the frog at 0:13, it's fine to just roll through it. Similarly, it's fine to roll through any of the wheels if you find avoiding the bees to be too precise. Hitting anything only incurs a small time loss of 5 frames (0.083s).
At 0:23 a shell jump is required to go high enough above the screen to stand on the tall wall.
The repeated midair spin-dashes from the high platform help cover extra distance without flapping - you don't need to do all 4. It's possible to glide between the final two dragonflies and land directly on the goal, but bouncing off the first one is likely faster as it trades 3 freeze frames for less speed lost due to flapping. Remember to hold jump while flapping, then release jump before bouncing the dragonfly to reach the goal as fast as possible.

Any 29 is good on this stage, but a low 30 is fine too.