Steam Hero mode:Complete the game after defeating Baron Von Smog to unlock Steam Hero mode. In Steam Hero mode, you can play against the Bosses that were defeated in Story mode.Credits option:Complete the game after defeating Baron Von Smog to unlock the Credits option.Steam Villains:The 12th Boss encounter is against the Steam Villains. Defeat the first 10 Bosses in Story mode without losing a match. After the 10th match, the Steam Villains will appear before you reach Baron Von Smog. Defeat them to unlock them in the Steam Hero mode.