There are four main enemy categories in Mass Effect: Andromeda—Kett, Remnant, Outlaws, and Wildlife.
The kett are the primary antagonists in the game, so expect to face off with these hostiles frequently as you progress through the main mission (Priority Ops). Like structured military units from the Milky Way, these aliens are armed with firearms and explosives.
The Remnant are VI (virtual intelligence)—unlike the geth who are AI (artificial intelligence), they are not self-aware and are simply programmed to defend themselves and their vaults.
“Outlaws” is an all-encompassing category of factions who’ve gone rogue. This group consists of several species, including angaran extremists known as the Roekaar, various pirate outfits, and two warring factions on Kadara, the Collective and the Outcasts. Most Outlaw-type enemies are found in optional mission areas like Elaaden and H-047C, as well as in Loyalty Missions.
While most wildlife enemies are minor annoyances, a few found on Havarl and Voeld are deadly.