I've recently seen a suite that has a ready made setup to compare sections of asm to the original.
Perfectly matching the full game or even binary isn't necessary, when you already split the original apart into finer chunks, since you want some better feedback on exactly what sections are wrong.

For a basic example though, if you compile to an elf for example you can take out the code section and there'll be no metadata. Actually gcc already builds reproducibly by default, even with the metadata section. It doesn't add any timestamps nor version info.