Inventing your own programming language for your personal project is a TERRIBLE idea, and will likely doom the project in the long run.
Languages require a huge amount of support, and you're going to be way too busy building an RPG maker to properly support a whole language. That means you're just going to wind up with a shitty unsupported custom language no one wants or knows how to use.
Terrible idea how so? You just said it's a personal project. What's the harm in learning and doing what you want? :)
> Inventing your own programming language for your personal project is a TERRIBLE idea, and will likely doom the project in the long run.
It's something that everyone should do at least once, ideally on a hobby project where it wouldn't be that hard to rip it back out if needed.
Wouldn't Lua be the classic/obvious choice for this application since it has such inertia [1]? I remember RPG Maker supporting Ruby back in the day but a lot has changed in the past 20 years...
[1] https://en.wikipedia.org/wiki/Category:Lua_(programming_lang...