Hi,
I have the following glitches/effects with the linux version. Everytime I level up a character the portrait icon becomes extremly lowres/blurry. I couldn't upload the images, always received an error "This upload failed", so I put them on my own site.
See: https://kiza.eu/media/stuff/poe_levelup.jpg
If that happens the main menu looks like this: https://kiza.eu/media/stuff/poe_levelup_2.jpg
The effect is 100% reproducible, saving, restarting the game and loading the save fixes everything.
Creating a new character has the same problem. The chosen portrait is very blurry: https://kiza.eu/media/stuff/poe_newchar.jpg
If the game starts that character portrait is also blurry. Once again, saving and restarting fixes it.
This may be impossible to debug (I'm quite away of that , but here are relevant system infos anyway:
Radeon 8670D (it's an integrated one in the CPU AMD A10-6700)
It's a Debian 8 (Jessie) with everything updated and the open source radeon driver (_not_ fglrx). So software versions should be around the latest version of most packages. Probably what Ubuntu 14.10 has.
Game version is 1.0 from GOG.