Bill the Demon is a side-scrolling platformer. The player is a Demon called 'Bill', who wants to impress the other Demons by getting an autograph from the Devil. In order to do so he has to pass all nine circles of hell.
For the Flash version of Bill the Demon some changes were made: One additional level was added, the background music was removed and the difficulty of the game was lowered.
The Flash version isn't exactly a port of the original Macintosh version, since the developer had lost the original source file. So it was necessary to extract the date from the original and reverse engineer the game.