A few years ago I created custom code that can be run in Pokemon Gold and Silver through Arbitrary Code Execution that would randomize the game. It is definitely not optimal but it was a great learning experience and I'm still pretty proud of it. If you'd like to try it out for yourself, you can follow the guide below!

Arbitrary Code Execution is a form of glitch found in old video games- most famously Pokemon Red/Blue, Super Mario Bros. 3, and Super Mario World. ACE is where the user will put multiple variables within the Random Access Memory of a game (or RAM) that, when interpreted as assembly code, will have various beneficial effects (such as skipping to the end of the game). Programming ACE requires the programmer to have an understanding of how the game system works at its core, as well as a strong understanding of the assembly programing language. It is tough to learn, but the results can be very rewarding and fun!