Well, I think there's the slight possibility this isn't a fake.
I think the big board they soldered together is just part of the controller for everything.
The big magnet is turned on all the time.
All the balls have smaller boards in them, like the ones in 0:53.
They consist (mainly) of a electromagnet and some circuitry around it.
Think about what might happen, if it is a electromagnet than can be switched on and off by sending a signal.
If you use camera tracking on the balls, you could disable them, if they get to high.
They get non-magnetic and fall to the ground.
If they are to low, you just reenable the magnet and they go up again.
The reason why the ball don't just form a big ball under the magnet is, because they all run on the same frequency.
If you turn off one ball, all balls turn off.
With this, not all balls can reach the same height.
What do you think of this?
apex