Couldn't tell you how many there are but I'm up to 12 and that's not enough.

I'm not convinced anybody has found them all, yet. No one has the achievement on xbox so I'd bet the few people on steam who have it used SAM.

I wonder if the 10 at the credits count too.

I think there are 12, but the problem might be that you have to get them in one playthrough. Replaying the game and collecting the missing ones doesnt unlock the achievement.

And the credits skulls dont count.

I've got 12 in one playthrough. Do you mean in one sitting? That would be dumb if that's the case

No not in one sitting, just in the same playthrough.
Might be bugged.

Yeah, one sitting would be too evil. Maybe I died after picking one up, got reset before that point, and forgot to pick it up again.

Um, okay. Just reached the 12th artefact on my hardcore run and the achievement popped. Looks like I did forget to pick one up again!

Does anybody have a list of their locations yet? I looked high and low but must have only finished the game with 4 or 5 collectibles at the most :p

UPDATE. Here is the combined list of all12 locations:

1. Orb Purification Plant: After jumping over the pistons inside the factory and defeating the flame wielder, scale the ledge to the right of the doorway. Continue to the end of that room.
2. Auxiliary Rotary Crane: After rotating the crane (RC-325). Continue left on bridge, jumping over the gap.
3. Landing At The Ore Offloading Facility: This area begins with grappling. Upon swinging to the third platform, double jump to the right. This hidden area of platforms leads to an artifact.
4. Lost City: At the water puzzle. After bringing the box up to the second story using the turnstile, move the box to the NE corner. Use the box to jump up to the ledge.
5. Timber Rafting: On the log ride go backward a few rafts and the artifact is on the last one.
6. Abandoned Mine: At the spot where you encounter the first possessed demon beetles. After killing them head over to the rock wall on the right. Jump up to the top and it is inside an abandoned cave.
7. City of the Dead: After orb challenge. Before climbing the vine, head left and there is a box in the wall. Move the box and it is behind it.
8. Top of the World: After defeating the demon priests at the courtyard you must go left with the grapple hook. Afterward, head toward the bridge and about halfway to it there is an opening on the right with an artifact.
9. Rainforest City: After gliding across some rock platforms you end at a mountain cliff with a rope bridge behind you (right before the chieftain hammerhead battle.) The bridge has sections missing, but can still be crossed. At the end are some spirits guarding the artifact.
10. The Draw Bridge: Continue to block the fire boulders until the slab is in completely in place. Then instead of going down it, make a leap of faith double jump and glide off it's right side. You will glide onto a platform where the artifact is.
11. Dark Jungle: Just past the worm infested swamp, there is a platforming section. At the second platform, look to the opposite end of the cliff to the left and there is an alcove and vine on the wall. Double jump and glide over to it where there is a collectible inside.
12. Towards the Mountain of Time: After killing the flame wielder go to the left under the stone archway.

There's a decent list on the only guide on gamefaqs. It's only missing the one right at the beginning of the floating logs ride, and the one in the spot where you encounter the first possessed bugs.

Thanks Cosmic! I combined the lists together and updated my previous post. So is there only 10 collectables? You had mentioned 12 earlier. I started a new game and got all 10, but the achievment didn't come up for me.

Gah, sorry, I'm being very dumb at the moment. For some reason I thought he had 10 and I stopped looking after I spotted the first 2 he missed. Let me remember where the next 2 are and I'll update this post with them.

Edit:okay, one of them is at the point where you're trapping boulders coming down 3 lanes to move a massive stone slab. Once the slab is in place, instead of running down it make a leap of faith to the right and you should land on a platform with it on.

Final one. My memory's so bad I had to watch a playthrough to remind me. Near the beginning of Landing at the Ore Offloading Facility there are a series of swing points. After the third, instead of carrying straight on you can make a jump to a platform on the right. It's on there. That should be no.3 on the list

Originally posted by Cosmic Schwung:

Gah, sorry, I'm being very dumb at the moment. For some reason I thought he had 10 and I stopped looking after I spotted the first 2 he missed. Let me remember where the next 2 are and I'll update this post with them.

You hero! :D

Thanks again for all of your help, that was it! It unlocked with those 12. I updated the list.

No problem. You should add that list to the guide section. I'm sure there are more than a few people who'll be wanting it.