In the Building stage, add attacks to the boss to make the bossfight longer. Also, customize the platforms and the player's health. Then press "Test" and let the fight begin. Arrow keys to move. What the buttons at the bottom do: Circle with arrow: Undo last attack added. X: Clear attacks. Square with arrow: Save your boss with a code. Cloud with arrow: Load a boss through a code.
Hopefully I fulfilled your demo expectations! Save/Load, Music, and lots more attacks! :^) Songs: couldn't remember all the names, but they are all by Trivial Decadence. Comment your bossfight codes! Removed cloud capability in 1.4. :=( but you can still save/load and share in the comments! @u@