Achievements got deleted.

[Rumplestiltskin]

I installed the game on a new computer about a week ago. I just noticed that the achievements got erased. I was only missing one achievement before but now most of them are gone. The only ones I have now were unlocked from playing again. I do not have Steam cloud enabled so it's understandable that my game progress was lost. Achievements shouldn't disappear though. I didn't even know it was possible for a game to delete them once obtained.