Achievement name : Shoot for the Moon:
Description Defeat the Moon.
:Spoiler: So basically this is for beating the last boss witch turns out to be the moon all you have to do is stand on the alien pads and TK the markers around you into the huge creatures eyes witch with most games takes three time once the last eye is punctured you need to pull the alien machine out of its mouth with TK then fly toward it dodging the debris coming at you once you arrive activate the codex and bam sit back and enjoy the credits. You should also get the achievement Get on my level when you finish the credits if this is your first play through. Enjoy and I hope I helped out.