If you were lucky you’d get the source code and assets for the game. But many home computer ports and early console ports weren’t so fortunate. You might have

If you were lucky you’d get the source code and assets for the game. But many home computer ports and early console ports weren’t so fortunate. You might have access to an arcade machine, or maybe just a video recording of a play through. It was up to the developer to mimic what they saw. Of course, the target system would limit what you could do.