Setup. Goal. Attackers start 20 metres out with a ball each. Keeper on the line.
How it runs. Attacker's first touch is the trigger. Keeper comes off the line, attacker dribbles and tries to score or go round. Six seconds per attack. Attacker becomes the next keeper.
Make it harder. Start attackers from an angle. Then every attack begins with the keeper passing the ball out to the attacker, weaker foot.
With 4 keepers. One keeper, one attacker, two in the attacking queue.