all you need to do is hit them with your power ups
They are safe, as long as a small child doesn't try to eat or break them.
Those are called Newton's cradle. It is a device that demonstrates conservation of momentum and energy.
You must complete the stage you are on fast, get lots of rings, get those little balls of power aka red,yellow, and blue and that's it. Another thing when you break a metal box you will find a key collect them and don't let any enemies hit you. When you complete the stage and you have the key you might get a chaos emerald. After you get all of them go to the right and you might see METAL SONIC.HARD
The spiky balls that fall from trees are called "sweetgum balls" or "gumballs."
Those little spiky balls that fall from trees and can be found scattered on the ground are called "sweet gum balls" or "gumballs."
There are a number of names for the balls - generally they are called zorbing balls or OGOs.
The white balls they throw at the winter part of their concerts are styrofoam balls and are supposed to represent snowballs.
Ebonite makes those bowling balls.
Ball Pools
The dollor store
Most balls are indeed hollow; they have air pressure inside. However, there are balls that don't have air. Those ones are not hollow.
These balls are nice balls. I like to shuffle with them to the party rock anthem. then we play spot the ball. hehe its so much fun! i love those balls in the yard.