Victorian Steampunk Mode
Beat the game once to unlock Victorian Steampunk mode. This mode is completely aesthetic. It changes the main characters' names (i.e. Sir Bakley, Geardwarf) and faces to something more "classy."
Deathtemple
Accessing the Deathtemple requires doing five tasks throughout the game that involve refusing to give certain items to people. First, at the beginning of the game, do not give a neo-shekel to the child at the church. Next, in the Neo New York Sewers, do not give the bum in front of Dr. Allard's office any neo-shekels. In Proto Neo New York, do not apologize to Wildman, who lives in the house next to Juwanna Mann. On Liberty Island, do not give the Poleshaft to Octavius Steambrast after beating Diabeasty. Finally, in the B-Ball Dimension, do not give Dick Vitale any neo-shekels. If all of these requirements are fulfilled, dying during battle will cause you to be teleported to the Deathtemple instead of being sent to the Game Over screen.