[christoph]

If you search google for their Skies of Arcadia nfo file, you will see this is clearly what they claim. I won't link to it here due to other material hosted on those sites. The trainer injected into the executable also makes this claim (you can view this on pouet.net).

I have little reason to doubt their claims given their clear technical skill spanning multiple console generations (Echelon might have only been associated with the Dreamcast/PS2, but it's obvious that their 'group' were behind multiple other, very highly technically accomplished scene groups).

Access to the source code is even a possibility - at one point they routinely released games weeks or even months before street dates.

http://dcemulation.org/phpBB/viewtopic.php?f=34&t=97250 is worth a read for an indication of some of the shenanigans that were afoot back in those days.

[voltagex_]

Wonderful. I love things like this. In these days of Steam DB and people scrutinising every byte, it seems like the easter egg / message from the developer has gone by the wayside.

https://tcrf.net/The_Cutting_Room_Floor has a lot of examples of left over / hidden content but nothing as cool as a message left for a particular group.