+Make sure the game doesnt stutter at 60fps.
+Slectable Refresh rate.
+21:9 and Multimonitor support.
+Instead of increasing the field of view, just scale up tge game when increasing reaolution.
+Some sorts of filtering options for higher resolutions.
+slight motion blur option (One like in Resident evil 6/Fifa 16).

+If its ever going to be released on Steam- please dont enable VAC cause it will ruin the modding part.

+Support for dual keyboards for double players. (I mean its already possible but the same buttons can't be used. So use raw input to maks it possible somehow).

+Support for seperate monitors for double player.


These are just some ideas I got in my mind. Maybe some of these can be implemented.