Baseline (Widescreen) Solution & Issues
The FOV can be changed if needed by editing the Video.scr file under: %localappdata%\techland\cojgunslinger\out\Settings\
Add the following line:
ForcedHorzFov(xx) // Forced horizontal field of view angle measured against 16:9 aspect ratio; 80-110 degrees, def. 82.72. Partial support only.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Eyefinity / Surround Specific Solution & Issues
Due to the engine's limitations on the number of objects it can display at once, ammo crates and enemy cover is often invisible until the player gets close, particularly problematic in the case of enemies holding doors as shields. Thus enemies will appear to be out in the open, but cannot be shot because they're actually behind invisible cover.
The HUD does not appear for many Eyefinity and Surround users, though the Cross-hairs are still present.
4k UHD Specific Solution & Issues