Assembly code is for writing C compilers, and C compilers are for writing Lisp interpreters.
Back in High School in the 80’s me and a buddy wrote a Z-80 editor assembler in TRS-DOS BASIC.
It was not rocket science.
True, it was computer science.
I never did get very far with the TRS-80 Editor Assembler, but that was my first exposure to such things.
I also remember the BASIC code for the Dancing Daemon which was replete with PEEKs and POKEs, such that much of it was written in machine code.
Exactly how we did it too. We created the editor/assembler that peeked to see what was there and display it in Assembly, Hexadecimal, and ASCII.
You could edit whichever version you wanted and it would Poke it into RAM.
You could also save swaths to a file.
Anyone who thinks OP asking about Assembly with this meme should play the game Turing Complete. It’s great. You have to design a computer all the way from the most basic logic gates (I think you only get a NAND gate to start), designing an ALU and CPU, creating your own machine language, and writing your own programs in the language you designed, and it’s all simulated the whole time. Machine language is pretty advanced as far as things go.
From your description this sounds more like a job in IBM’s R&D department than a game
So do many simulation games.