Kirby 64: The Crystal Shards/Aqua Star 4

Underwater Cavern

As the name suggests, the stage takes place underwater. There are six sections, and being underwater will cause all of Kirby's movements to be slow.

Miniboss:Blowfish
The blowfish is hard to avoid if you are stuck following the current in the Blowfish's opposite direction while trying to inhale enemies to shoot back at him.