Is there not a manual way to adjust the game brightness when running in a window? Everything is just so dark it is annoying.

Anyone? I figure it has to be tweakable somewhere, I looked in the prefs file but didn't see anything there.

Having this issue as well, would love some advise on how to fix this.

Change your settings through either your graphics card settings or through windows if your windows supports it. Note this will change your desktop gamma/brightness/contrast as well since running in windows mode uses the desktop's settings.