
Originally Posted by
Fluttershy2
This get nowadays done in Nostalgic servers. However, you need understand also this takes a long time. The reason to this is because in later versions Nexon heavily increased the overall damage of everything, which means the newer mobs are unkillable on lower versions standards, unless you tweak it, which takes a lot of times and practice. Also, if you example take Pink Bean, it has already features (I believe guard or something) which is unsupported by any version lower than 72, similar for other bosses from newer versions.
This is already a problem though. (General) "nostalgic" people are really strict. This means a custom NPC or a hacky way to implement something could already be very negative, because it makes the server look very "Private Server"ish.
Most nostalgic people like 100% authentic GMS-like text and GMS-like functions, which means if you run a 0.62 server you can pretty much only implement the features that are coded within the client in 0.62 (packets). Likewise, if you run a 0.83 server only the 0.83 features.
There's also many servers that tried go in the custom way, but most heavily custom servers (especially those aiming at nostalgia) fail horribly due to lack of interest.