Well. Here is how it works really:
1. There are two groups. Spazoids (the main group), and others (Not Spazoids, but are built like the Heartless). The first three chapters have you battling the Others. They are:
* The First Chapter is set in the mountains. You must defeat Kingdok.
* The Second Chapter is set in a sports arena. You must defeat Ryan Leaf, the ultimate sports flop.
* The Third Chapter is the first Spazoid chapter. Even though Deven did not focus on them, this chapter's foes will involve comic strip foes. The final boss is... the Family Cicus.
* The Fourth Chapter is the final Earth chapter and the chapter where you tire out the Spazoids and wipe them off the face of the Earth, save the leaders. This might be Deven's chapter (I'm doing almost all others)
* After that, only the Others remain... and Dr. Forrester's Movie Monsters.