So, I've been digging at those ELF files for the Gems Collection version of Sonic CD. While objdump could be used to extract function and variable names, I noticed that it wasn't able to parse the .debug sections. The thing is that, there were definitely more symbols to extract, such as structure member names. Today, I did some more digging, and found this thread, which actually talked about my very issue, but for DDRMAX2. The very last post then took me to this post, which showed that someone successfully managed to extract data from the .debug section, and provided a batch script on how they did it. Gems Collection so happened to have been compiled and linked with the same tools as DDRMAX2, and I found an archive of those tools on archive.org, with cracks. So, I installed them and ran the Sonic CD ELF files from the PS2 version through the linker's disassembler, and... It worked. It's pure beauty. A much more complete dump of symbols with disassembled code from Sonic CD is now available.