I managed to get 87832681 points although I don't have my rush units hyper maxed...
Cool Japon and Bento Special combos.
Manic Lion (30), Bullet Train (50), Yukimura (35)/A. Bahamut (40) (interchangeable).
Strategy: Spawn a 2 M. Lion immediately one after another. At 1000¢, spawn Bullet Train and a M. Lion right after when money is sufficient. Then, spam Yukimura or A. Bahamut so that you destroy the base in minimum time.