I only know so much, the idea is a simpler version of the game for people who can't be bothered to set training regimes and indepth stuff like that, i.e. more similar to older Champ Mans, less features but means you can get through a season quicker.
Classic Mode - where you can play a stripped down version of the game, more similar to the old Champ Mans.
Challenge Mode - where you get dropped right into the middle of a scenario, a la Slade taking us over and keeping us up.