Rock 2

Wait for the first column to fall and run underneath the rest. You can get underneath the first column, but it requires triggering it late with a precise jump. Waiting gives you time to throw away the yoyo powerup, which is useful for clearing the Sparky and Kacti enemies earlier in the level. If you're not comfortable with jumping underneath the Bouncys (middle), you can keep the powerup longer and get rid of it later (right).

Navigate through the mini maze to get Shard 1. There are several possible variations not shown here, such as floating up versus jumping up, or changing where you use fire.

In the next room, fire across the abyss to get Shard 2. In the next room, I like to do one fire on the ground to get the right spacing for avoiding the Kapars, but this requires relatively consistent single fire canceling. Take the last of the crushing platforms up to get closer to the exit.

In the Dedede section, it's faster to jump up the chains instead of climbing up them. It's easiest to damage boost off of the Galbo's fire breath to get up, but if you're low on health it's possible to jump past it. After grabbing Shard 3, jump before the pit to both save time and to avoid waking up the other Galbo too early. In some of the chain jumping sections, you can reduce your horizontal momentum by turning around twice to grab the chain at a better location.