Do you need to collect 500 milk in one game? Or do you need to collect it during all games you play? Can this be done in relax mode? Help me please if you have some info

Do you have any feedback about this game? We'd love to read about it

Just bought this game, such potential for challenge - how on earth do you rotate the pieces? Tutorial says 'space bar' but nothing happens. If I could do this I'd be a very happy cat.