I don`t know about other platforms, but i cannot find gamma configuration option.

It would be nice to have one.

+1 to balance manually the diversity of displays (and eyes)

Why does the game need to do this? Most operating systems and video drivers have a way to adjust gamma.

try xgamma -gamma 1.4

because I'd like my gamma to be different when i'm running vo than when i'm running other fullscreen apps or when i'm on my desktop.

Per-application settings are always nice to have.

You could make a wrapper around vendetta that runs xgamma to save the current settings, changes them, starts the game, and then resets them afterward. That way you don't have to wait until the devs add an option, if they even bother.