The number of batteries doubled between operations, allowing them to defend more areas and engage more rockets. (academic.oup.com)
For Campaign there's a decent number of missions, each getting progressively harder, with more rockets to defend, pathways to manage, and enemy variations to fight. (gaming-age.com)
For more details, check out the interview itself, and then get back to playing, yet again, lots more Rocket League. (twinfinite.net)