Hi, thanks for the reply, but I fixed the problem on my end. To clarify, I knew that artifacts disappeared after you collect them. The problem was that I was following a text-only artifact FAQ which wasn't all that clear and I assumed that since I couldn't locate an artifact in a specified part of the level that I had somehow corrupted the game by running both trainers at the same time. Anyway, after some more careful exploration of the area I was able to find the missing artifact and get my 100% completion.
As a side note, I really enjoyed the game, I had previously played TR: Legend, which made purchasing TR: A pretty much a no-brainer. I do have one slight criticism of the game though, and that was the excessive amount of death traps on the second to last level: The Great Pyramid. We got a little bit of a taste of what was to come on the way to the last piece for the Obelisk with the saws and the stone blocks and the split second jumps, but IMO they went a little overboard with the timed jumps up the lava flue in the Great Pyramid. I must admit, the scale and the graphics of the room were impressive but after reloading multiple times from the same checkpoint I almost threw my keyboard and mouse at my monitor in despair. When Crystal Dynamics gets around to making the next TR, I hope they rein in the next level designer who envisions such a similar room and cut it down to maybe 3-4 jumps, as opposed to the 6-7 jumps with no margin of error. It will save me a lot of frustration and throwing my arms up into the air
