This is a massive undertaking... building a whole language + IDE + engine from scratch is insane. I am curious: what made you go with a custom language instead of just embedding Lua or something? Was it a learning thing, or do you think Exp brings something Lua (or GML) doesn't?

Apart from "I have fun working on this", which is always legit, what's the point and who's supposed to use it? What'd be the benefit using with or working on it over e.g. Godot, which is, imo, pretty much the open source way to go if you want more than an IDE and libs/code you'd use to make a game. It's also written in C# and offers GDScript as a more lightweight programming language with C# being ready to be used for when it's necessary.