MrDetonia: I'm running Debian Testing with a Radeon HD 6570 GPU, OpenGL version 3.3. Graphics drivers are the open source Radeon drivers, with non-free firmware blobs installed.

The game starts fine, and the initial cutscene plays with no issues,. but when I actually enter the game the rendering is completely wrong. I'm getting random textures all over the place, and there's no visible structures anywhere.

Screenshot: https://i.imgur.com/MuqyIzo.png
hpl.log: http://pastebin.com/Xvp1uf5Y

Has anybody else had this kind of issue?

MrDetonia: This fixed my problem. Thanks for the advice!