You are not misunderstanding, friend! There are a lot of fanmade Pokemon games with different mechanics and features, like having every single pokemon from gen 1 to gen 9 available in the same game and stuff like that.
The 2 most popular types of games made by people are romhacks and RPGXP games.
The first one is (as the name implies) a hack of an original gba or gbc rom to change maps, mechanics, music, pokemon, items, etc., that must be played via gba or gbc emulator, but these are limited to the maximum space capacity of said games, which is 8mb for gbc and 32mb for gba (although people have managed to fit a lot of content even with those limits).
The second one doesn’t have a space limit and could potentially have infinite content via randomly generated dungeons and some other cool things in addition to the ones mentioned for romhacks. RPGXP games have an exe file that must be run through proton’s compatibility mode.
You are not misunderstanding, friend! There are a lot of fanmade Pokemon games with different mechanics and features, like having every single pokemon from gen 1 to gen 9 available in the same game and stuff like that.
The 2 most popular types of games made by people are romhacks and RPGXP games. The first one is (as the name implies) a hack of an original gba or gbc rom to change maps, mechanics, music, pokemon, items, etc., that must be played via gba or gbc emulator, but these are limited to the maximum space capacity of said games, which is 8mb for gbc and 32mb for gba (although people have managed to fit a lot of content even with those limits).
The second one doesn’t have a space limit and could potentially have infinite content via randomly generated dungeons and some other cool things in addition to the ones mentioned for romhacks. RPGXP games have an exe file that must be run through proton’s compatibility mode.
You should try them! Both are extremely amazing.