Go back even farther and you'll get to a point where entire games were written in assembly and assets might been written with a hex editor (and even that description might be higher level than what they actually did).
My dad had a computer class in high school that involved filling in ordered punch cards and then they'd send them off to a university to run them on their mainframe and they'd send the output punch cards back. That wouldn't have even been assembly, it would have been machine code, though they probably marked the punch cards to be easier to remember what bits meant what. But it would take like a week to find out there was a mistake in the code.
Sounds crazy from where we are today, but that's all they had at the time. If you wanted to do something awesome, you could either give up, invent a better way, or just buckle down and do it the hard way.