I contacted 505 games regarding the main game:
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Hello,
On May 10th, you released Eiyuden Chronicle: Rising on GOG and Steam. That being said, we have yet to see Eiyuden Chronicle: Hundred Heroes on GOG's upcoming game list. Do you plan to release this title on GOG like you did with so many other titles?
Cheers
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Got typical pre-written crap for a response:
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Hello,
Thanks for contacting 505 Games support!
Unfortunately, we cannot disclose any information regarding future changes or additions to our products outside of information already available through our official channels.
For more information on future updates and games, please stay tuned to our official Twitter channel @ 505_Games and the website at 505games.com.
Please do not hesitate to contact us if you need further assistance.
Best regards,
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In short, if we don't have the main game in the upcoming GOG titles and I get this sort of response, for me, it means that the developers don't want the main game on a DRM-Free shop.