Welcome ArchV! <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
I'm not sure which modes you mean? Throughout the game, you will have full control over all party members (up to six) simultaniously.
I believe the game comes with a spare pause key (space bar) because of the frequency you'll be hitting it. <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
