@Romariel Depending on how literal the reading of the game is, I can picture a few different ways to make it a game... you're fishing with a magnet on a line, trying to pick up as much iron sand out of a sandbox in a certain amount of time, whoever gets the most wins the prize (or, as an individual game, trying to get above a certain weight). Or there are magnetic bearings tossed in a sandpit and you're aiming to get the largest one.
In either case, they're kind of weird, but viable.