Any5-3

This level features some platforming, some swimming, an intended shortcut and a minor clip.

Optimal

Assuming you enter this level as Marbles, you'll need to swap to Checkers, ideally before the first water section since Checkers moves faster in water. Dropdashing into the water only saves a few frames.
When exiting the water, try to jump as high as possible. Be careful when dropdashing over the raised edge platform - if you are too close to it you can snap to it, losing the height needed to get above the P shooters.
The triple jump out of the water should be maxed out in order to land on the third P shooter. It's possible to "uppercut" the second P shooter, bounce to the fourth, and make it to the shortcut without dropdashing, but as the piggyback throw causes you to drop under max speed, this ends up being slower as you lose time while crossing the shortcut.
Time your rolls and jumps carefully over the shortcut, as walking along the ground without rolling will lose speed. Doing 3 large jumps instead of 4 small jumps is possible too (demonstrated below).
When exiting the shortcut, aim for any of the raised edge platforms. If you land in the middle part of any platform (or fall down the gap), you will need to dropdash over the beaver.
The roll-jump after the bubble at 0:18 is enough to clear the gap over the spikes from either the upper or lower platform.
Piggyback before jumping to the salamancer to prepare for the wall clip. This clip must be set up manually - touch the wall, then quickly tap left and press your "clip button" to go through. Ideally you want to be as low as possible to land in the water quickly. The fastest way to do this part is to release jump to low bounce off the salamancer, then repress jump to "float jump" to the wall if needed.
Landing in the water cancels the piggyback. Turn left and swap repeatedly to pass through the wall. 4 swaps are needed to get through, leaving Marbles in front. Although Marbles swims slower and Checkers is needed in the next level, Marbles can finish the level faster and more easily with a shell jump. The Checkers end is shown below.
The clip messes up the camera, changing the enemy patterns at the end. The first Pipstick may fall and hit you, but it's safe to roll through. You must blindly jump between the next pair, aiming for the small edge platform.
From here, the piggyback and shell jump are straightforward. Mind the pair of bees at the end. If you don't jump off the small edge platform at the end, you can just bounce off the salamancer straight into the goal.
If the camera is in its normal (centered) position, the blue frog at the end will jump up to you and you can bounce off it, allowing you to glide less, maintain speed and avoid the end bees more easily. If you have a centered camera at the end for any reason, aim for this frog.

A time of 36 or better is good on this level.

Alternate: Checkers end

This route is slower and more difficult.

The shortcut is crossed with 3 large jumps instead of 4 small jumps for demonstration purposes. Choose what method suits you.
It's barely possible to cross the entire gap at the end with a maxed out quad jump. It's still slower than crossing with Marbles due to the fact that piggybacking and dropdashing invoke freeze frames and slow you down anyways.