Is the problem still occuring?
Yes, the problem is still there. I have two more images that show the issue even better on the game start menu(radeon first, then intel):


If it is you could try to update your graphics card drivers and system.
I use archlinux, so all the involved packages are up to date, in particular:
Linux 3.13.2
Mesa 10.0.3
LLVM 3.4
A week ago I wanted to try using git versions for everything and see if the issue was fixed, but I need my laptop for my exams in this period, so experimenting too much is not a great idea for the time being...
I also tried using the standalone version downloaded from torrent on humbleindiebundle.com, same problems occurred.
On a side note, is it possible to know which version I am using? It appears there was an update on steam, but I don't think i got it...
If you need some help debugging, just ask and I can post outputs/debug prints here...
Thanks for your support