15 Total levels. 14 Playable ones.
Be player 2 in the halo 3 co-op campaign. Or, play the Arbiter levels in halo 2.
well what you do is beat all levels on halo 3 then you get the cool armor
13
ghost town and covenant
Chieftains are one all the levels except floodgate, Cortana, and Halo.
Tsavo highway and Floodgate
there are three levels in halo CE anniversary
If by parasites you mean the spores on the levels floodgate,cortana and halo no they do not count as kills so sorry.
they are hidden around the campain levels i forgot whear most of them are
you hav 2 complete the game
Yes, there are three Easter egg levels in Halo 2
HALO Wars has the most levels. But if you're just talking about the regular first person HALOs, then HALO 2 has the most levels.