There's been a pretty robust rom-hacking community for Super Mario World that dates back to the 2000s, and it's something I always thought was really cool. It's

There's been a pretty robust rom-hacking community for Super Mario World that dates back to the 2000s, and it's something I always thought was really cool. It's led to some really awesome games coming out that are far more interesting to me being that they're built off an antiquated engine that ran on a 16-bit console from the 90's. There were plenty of other custom Mario level programs out there, like Super Mario Bros X which was an engine entirely made from scratch for PC. But that never interested me nearly as much, because people were writing Lua scripts that could do anything, and could leverage modern PC processing power. I thought it was way cooler to see what people pulled off when having to deal with sprite limitations, and having to write all the code in assembly. It really bred a whole other layer of creativity. Plus a lot of the games could actually be played on a physic console if you loaded the ROM onto a SNES flash cart.