I'm down to two achievements for this game, Untouchable (getting through a level without getting hit/losing health) which I feel like I should have gotten a couple times now and Tech Curator (find all the tech orbs). 
 
I've got 4 levels let that are almost complete but not quite.  I've got two levels at 99% and I've gone through each level at least 4 times finding nothing new.  I was so close to finding these that I decided to go for it and finish it off.  Now however I'm getting frustrated.  I'm not actually enjoying the game at this point, I'm only still playing it out of a sense of misplaced pride (trying to S-rank it).  I just wish more games would have some way of locating hidden stuff easier.  Even if it was after you've beaten the game on the hardest difficulty or some other requirement so it wasn't open right from the start. 
 
I'm mostly just venting a little here, taking a break from the quest so I can go back in with fresh eyes.  Alright, I'm done whining now, back to the game I go.  I really hope I finish scouring these last 4 levels before Tuesday because once I get Fallout in my hands I will probably never come back to Enslaved. 
 
*update* 
So now those 4 levels are all at 99%.  The lowest one previously was 93% and I found a group of them I knew I had missed (chapter 9, chasing the dog) but that wasn't quite enough.  Blargh.  That's probably 1 orb in each level left to find.

Seeing as I'm just talking to myself (didn't expect anything less as I was just venting really). . .  
Finally got them all and S-ranked the game.  Most of the orbs I was missing were in spots that were right out in the open but somehow I had missed.  One though, in chapter 3 seemed to be glitched. 
 
In case anyone else is trying at is at 99% on chapter 3 watch for the spot where Trip crawls through the hole in the wall and you have to climb up and around to rejoin her.  There is an orb directly on the other side of that hole.  Twice I saw it and as I dropped down to get it it simply vanished.  I didn't collect it, it just vanished.  I've read other people experiencing this too.  Some have reported jumping down as far away from it as possible and creeping up on it works.  However, the easiest thing to do is just to wait for her to crawl through the hole then hug the wall there (to the left of the hole if memory serves).  You can actually collect it through the wall without even seeing it.  Finally got that one and popped the achievement thus ending my time with this game, just in time for Fallout 4!

 @Phunk_King:  Now S-Rank the DLC!