So far I’ve found 2 achievements that do not work as intented.
First one is “Thanks for the advice”, on The Dig mission. It says you mustn’t kill any enemy units with the laser drill. However, if you kill the bonus structures to get the artifacts, you also fail the achievement, even though the display for laser kills is still 0. I would have no problem with this being a technicality (units, structures = same thing) - albeit an annoying one since it literally slows your progress in gathering artifacts and unlocking technologies - IF the laser kill counter would show the number of buildings kills too. As it is, I’ve won the mission only to find out I have to load a save an play it again because I’ve destroyed those structures and didn’t get the achievement.
The second one, which is 100% broken is “Contract saviors” on the Moebius Factor mission. To unlock it, it says you must train only scvs, medivacs and mercenaries. I’ve played this 3 times and failed to get it.
First time, I also build mules, which I considered might be excepted from that rule, due to them being calldowns. I also made bunkers, and siege tanks mercenaries, since I have access to them, and ofc upgrade buildings and supply depots. Failed achiv - ok, maybe the mules were at fault.
Second game, no mules, just bunkers, mercenary tanks, upg buildings, supply. Failed again - ok, maybe you’re not supposed to build bunkers either… or maybe mercenary tanks aren’t allowed cause you were supposed to do this mission before the dig and it’s a bug somewhere or something.
Third try, I didn’t build anything. No buildings, no supplies, not even a second refinery, I think I only made a medivac at one point and I’m not even sure of that. Still failed. The only problem I can think about with this one is that at the start of the mission, you get 2 neutral medivacs which unload 4 regular (non-merc) marines in your base, and then all of them convert to your color. So maybe the game counts those as units trained that you shouldn’t have, but there’s no way to prevent that from happening.
Will update this post if I find more 10th anniversary campaign related bugs.