Kirby (as stone Kine) can only look side to side but cannot move at all, even under water. This is a reference to the fact that in Kirby's Dream Land 2, when Kine has the stone ability, he is just the same as regular stone. It does not have any practical use.
Kirby (as stone Nago) can triple jump, but he does not go very high.
*All are similar to Stone - Kirby is invincible while transformed, and enemies are damaged when they come into contact with him.
Kirby turns into random stone animals, like fish and birds, that are heavy and indestructible.”
— Description • Official Strategy guide
Kirby quickly sculpts a stone statue of one of his six different friends. Each statue has it's[sic] own unique power. For example, the mouse can double jump better than Kirby can, and the owl can fly. Press B while Kirby's in the sculpture form to explode the sculpture's exterior, destroying nearby enemies. Kirby is invulnerable while he's inside the sculpture.”