It's been 5 years since the game used giant balls (
FIRST Overdrive).
I wonder if the End Game might involve lifting a large ball up high (8'?) and holding it there, similar to a seal balancing a ball? If that's too easy, maybe we have to climb on a platform first, but can't start until the last 15 seconds, like the minibot launching in LogoMotion.
That would be a great visual; 4 to 6 robots quickly climbing on platforms, then giant balls being hoisted up high!