The original Resident Evil 2 for the Playstation spanned two CDs. We had to get it on a single cartridge. But it's just a port, right?
Audio and video received most of the attention and were pushed and squeezed until they fit. Our focus on these assets, however, caused us to neglect other areas such as the animation data. We did manage to cage these beasts, too, but on our final burn we had to shave another megabyte off the video. This last megabyte took us under the critical point where the video suddenly went from very pretty to just a bit too obviously compressed."
...it was a lot of hard work due to the myriad magic numbers and hard-coded values in the RE2 code. We literally had to understand and reparse every single bit of data in the RE2 library. And we did, much to the credit of every programmer on the team. This created quite a few bugs but we sacked them all.
Though the original RE2 code was written in C, it resembled Assembly language more closely than it did structured code. Given that most of us are flat out reading English, the Japanese comments weren't particularly helpful, either.