Artifacts are special items which are hidden in certain levels. They alter the way the game functions when in use. Their effects do not take place upon picking one up; it has to be switched on from the character select screen after your game. They don't always appear in the levels which they are found in.

Artifact	How to unlock
Artifact of Command	Hive Cluster, if spawned, it will be in the top right corner of the map, climb across the ropes to reach it.
Artifact of Distortion	Damp Caverns, towards the top right section of the map, there's a small box that must be broken to spawn the artifact at the gate.
Artifact of Enigma	Sunken Tomb, there's a passage at the bottom right that you can reach by falling into the hole above it and pushing right to hit an invisible jump pad.
Artifact of Glass	Ancient Valley, up the left wall there's an invisible passage, after finding it you have to hit several timed switches then fall to reach the gate.
Artifact of Honor	Desolate Forest, there's a path in the mid left portion of the map, you'll need jetpacks or the Miner/Mercenary to make the jumps.
Artifact of Kin	Dried Lake, a wall in the right end of the map can be broken, after breaking it, hit the switches that are there.
Artifact of Origin	UES Contact Light, it appears when you kill the final boss with all of the other artifacts active.
Artifact of Sacrifice	Magma Barracks, hit the three switches and go to the artifact gate.
Artifact of Spirit	Temple of the Elders, there are sometimes platforms at the bottom right of the map when you jump off the cliff. Follow them to get this artifact.
Artifact of Spite	Sky Meadow, in the mid left area of the map there is a small portion of the ground that is cracked, use an explosive to break then go in the hole.