For the first glance:
• doesn't get reproduced on another graphics card vendor equipped PC;
• doesn't reveal on screenshots taken with Steam UI;
• perhaps you didn't disable Steam Beta to check if it goes away.
If all of this is true, it might be related to the game/driver issue.
Hello @Arandhras, are you still experiencing this issue on an up to date system?
Closing as support for fglrx has been dropped by the vendor in favor of mesa and amdgpu-pro.
Nothing extracted yet.
In any menu of the game the mouse cursor is surrounded by a filled white box; I guess it is an alpha transparency issue caused by my video card drivers, as this behavior isn't showing on my other computer which is based on an Nvidia GPU.
The curious thing is that the transparency issue doesn't show at all on screenshots, either taken by Steam or any other screenshot application.
Computer specs: