Thanks and Quick Question

Just launched the Force Engine to play Dark Forces for the first time, really easy to do, thanks for all your efforts. Upon initial launch, I was given an option to run the game in modern, retro or "x" (another option I can't remember the name of). I chose "retro" but was wondering if there is a way to see the options again or change this choice. I wanted to test the different between the retro and modern options. Thank you in advance.