This is the source code of the Famicom game "Bird Week", disassembled by DISASM 1.5 and redacted by me (cybermind) by adding proper lable names, variable names and code comments.

When you assemble this source by ASM6, you will get a rom file with contents identical to "Bird Week (J) [!].nes" ROM.

Bird Week is the most hardest official NES/Famicom game ever created in the lifetime of the console.