Emulating old computers or video game systems isn’t always about recreating childhood nostalgia or playing classics on hardware that no longer exists. Most of the time, this can be a great way to learn the mechanics of video game programming. Many older titles have source code available for anyone to browse and modify, and one of them is Pokémon Emerald. It was the first Pokemon game that [Inkbox] play, and added some modern features to it with this custom ROM file.
The first thing to add to this game was the ability for his Pokemon to follow his character on the overworld map. This is common in later games, but was not yet a feature when Emerald and Ruby were first released. [Inkbox] needed to import sprites from later games into the Emerald game file, convert their color palettes to match the game’s palette, and then get to work on the mechanics. Once it’s all done, Pokémon not only follow the player around the map, but are animated, moving in and out of their Pokéballs, and even jumping off ledges in a 32-bit believable fashion.
One of the good things about older games like these is that they’ve been around long enough to have source code or decompiled code, they often have extensive documentation, and the platforms they play on work are also well known. Pokémon Emerald is not alone in this regard; in fact, there is a huge Game Boy Advance homebrew scene that isn’t too hard to get involved in.