Originally posted by: avatar!
I was not aware. What exactly are the distinctions?
A reproduction is an aftermarket physical copy of an existing game. It looks like (or is supposed to look like) the original, real thing. A dishonest bootleg, if you will.
A hack is a game with the code modified to change an existing game (the "reprogram" that you thought repro was short for). They might or might not be published on cartridges. Some are good, whole new games that use existing characters and engines (Zelda Outlands, Mario Adventure), some are jokes or experiments (Sonic Bros), and still others are somewhere in between (Strange Mario Bros, Mario Forever). It might feel unfair to call these all by the same name, but I don't think the term is pejorative by any means. Same with homebrew (completely new, wholly original games) (Battle Kid, The Mad Wizard) and demos (not games at all, but programs that try to make the hardware do new and interesting things with graphics and sound) (CMC80s, Aspekt): some are better, more impressive, aspire to greater heights than others. But being in the same category doesn't bring them down and they don't need to be called something else.