Steam Heroes Steam Hero mode
Successfully complete the game after defeating Baron Von Smog to unlock Steam Hero mode, which allows you to play against the Bosses that were defeated in Story mode.
Successfully complete the game after defeating Baron Von Smog to unlock the “Credits” option.
The twelfth Boss encounter is against the Steam Villains. Defeat the first ten Bosses in Story mode without losing a match. After the tenth match, the Steam Villains will appear before you reach Baron Von Smog. Defeat them to unlock them in Steam Hero mode.