Fix for white screen issue on old GPU

Hi, I'm still working on implementing Steam Input. I have some problems with Menu controls. Character controls are working in test builds.

Some updates and fixes for the game:

• Added mouse button controls

• Fixed white screen on old GPU (use the lowest graphics setting)

• Fixed issue with throwing grenades

• Minor lighting and sprite adjustments

• Various optimizations for better performance

Thank you for being so supportive, and see you soon.

Ania and Marcin