I grew up playing 8-bit Nintendo games and I have always been fascinated with how the games work. Several years ago, I found a partial disassembly of the game engine for the original Metroid. I studied it and greatly expanded it. I was able to disassemble about 60% of the game. This was my first attempt at a disassembly so it is a little rough around the edges. Below are the 9 files that compose the disassembly. The code has been tested to reassemble properly and make a working game.

Metroid Defines Title and End Game(Bank 0) Brinstar(Bank 1) Norfair(Bank 2) Tourian(Bank 3) Kraid Hideout(Bank 4) Ridley Hideout(Bank 5) Graphics(Bank 6) Game Engine(Bank 7)