Switch

Switches are devices that appeared in Kirby: Nightmare in Dream Land. Smaller versions appeared in Kirby & the Amazing Mirror and Kirby Squeak Squad.

In Nightmare in Dreamland
You needed to activate each switch if you wanted 100% complete. The are often hidden secret doors and cannons.

In Amazing Mirror and Squeak Squad
In these games, they weren't as important as they were in Nightmare in Dream Land. They still were important for finding secret chests, 1UPs and Maxim Tomatoes.