User blog comment:Damac1214/Call of Duty 2014 Reveal Incoming, Details Revealed Throughout the Day/@comment-4921618-20140501181454/@comment-1916935-20140502043713

Aliens are pretty by the book. They really aren't strange or out there aliens like in Halo (think of when it first came out) or, to a lesser extent, Resistance. And the alien types in Extinction are really forms of enemies that a lot of horde modes have. Grunts, slightly more powerful grunts, tanks, suicide bombers, kinda just regular ol' horde mode fodder there. And fans have been requesting aliens ever since MW2.