After that the Li'l Bun Buns will come out. Buy your strong cats and project them with meatshields. Also, use your fast cats.
When you beat Li'l Bun Buns, the Zackie Pengs will come out. Spam your meatshields again and your strong cats. Zackie Pengs are attacking so fast and deals much more damage than some other enemies. For solve this, use your Cow Cats/Giraffe Cats. Spam them too, because they will die quickly and/or project it with your meatshields.
Another Li'l Bun Bun comes, spam your meatshields. If you have collected money from the enemies you killed, use it for the meatshields till you can buy a strong cat like Bahamut Cat etc. The strong cats you buy will attack Li'l Bun Bun with projection of meatshields. If you don't buy a strong cat, the Li'l Bun Bun will destroy your meatshields and defeat your base.
After that, the face isnt much of a problem, so you've already won. Onward to victory!