Complex sentence: After completing a game, a new option will be unlocked on the main menu which will enable the player to input a code for an alternate outfit, and more can be unlocked by completing further new games under special circumstances.
Split into simpler sentences: After completing a game, a code is provided for the player, along with a new option on the main menu, which will enable the player to input this code for an alternate outfit. More can be unlocked by completing further new games under special circumstances.