I sound like a broken record here, but are you up to date on the latest patches? If I remember the patch notes from the latest one correctly, achievements were one of the fixes.

yes ive done the file verification and even looked in the beta channel, the game reads me being at 1.2.1. but even restarting steam didnt fix the issue

I was just playing tonight, and noticed that an achievement didn't pop up until I quit the game. Previously they had popped up in-game. I'm guessing you've checked your achievements list outside the game, but if you haven't it may be woth a look.

Could you be more specific about which achievements exactly!?
I'm moving this thread to the bug reports subforum!

well pretty much all available achievements that could be earned from the white house map to the completion of the first world. am currently in the ice world and i just now earned my first achievement fo killing 50 ice bugs. another thing i might bring to note is that this only was earned after i launched the game as admin.

Yeah, mine won't unloack either. hmm

I've got two achievements bugged, rest have usually unlocked when restarting the game or starting a new level.

Bugged achievements for me are 'gunslinger' and 'Lieutenant', I have all but one weapon(electrocutioner which I can't pickup) max upgraded and I'm level 22.