Steam Acheivements not working

[Lense]

http://steamcommunity.com/sharedfiles/filedetails/?id=249582108
I should have some acheivements by now, but I have none. From the global statistics, I know that other people are getting them.

What could be causing this?

uname -a
Linux gravitational 3.13.8-1-ARCH #1 SMP PREEMPT Tue Apr 1 12:19:51 CEST 2014 x86_64 GNU/Linux