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.
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.
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.