Pacmania is a pseudo-3D version of Pac-man, where the maze is viewed from a skewed isometric perspective. Unlike the original, the maze is larger than the screen, necessitating scrolling. As well as being able to jump over the ghosts, Pac-man can now be told 'in advance' to turn a corner, saving valuable fractions of a second. The game was ported to a ridiculous number of platforms, including the aforementioned Sega Mega Drive, as well as the Master System, ZX Spectrum, C-64, Commodore Amiga and Atari ST. I don't think that there is an 'official' PC release of the game (but I could be wrong).