Once the peons are killed, a wave of Li'l Bun Buns comes out, and you have to stall the Li'l Bun Buns until their spawn rate decreases.
A standard anti-floating line-up will work, including Cameraman, Sadako, Sanzo, Angry Delinquent, and an anti-floating uber (eg: Warlock and Pierre the anti-Alien/Floating version). Fill out the rest with meatshields and Ubers or standard heavy hitters.
The level starts out with some weak peons to allow you to build money, send out meatshields and Cameraman Cat. Some Brollows will come out - your Cameraman Cats should be able to hold them. If you can build up enough money, deploy Warlock & Pierre. After this it's just a matter of spamming all your other anti-floating cats and Ubers or heavy-hitters.