The level starts by spawning a Scissoroo and a few Kroxos and Shibaliens. After attacking the base, a huge group of the three is spawned. After a while, more of the same eniemes are spawned, only this time with a few Black enemies mixed in. Eventually, the Aliens gradually get replaced by a horde of black enemies.
Fast AoE attackers will work well.
You must use 4 MS, Paris, C UFO or Jizo, also Macho Legs and some heavy attackers. When you get enough cash and you have summoned your main attackers, turn on Cat CPU. Good luck!
Note that if you have Takeda Shingen, this stage becomes immensely easier.