I also contacted the dev with the captcha issue, he was indeed very kind in his reply. I will paste his reply below. I also suggested the google captcha's to him, so yeah, without any further adue, his reply:
--- start of reply
I'm very happy to hear you enjoy the Realm so far!
I'm having little experience with accessibility and basically with coding in general, but I'm trying to catch up.
For the time being, I removed the old captcha from the registration page. This should no longer prevent people from signing up, as soon my work is done, I will use the google re-captcha. I hope this will both add some protection against bots and improve the accessibility for new Seekers.
If there would be other issues that prevent you from doing certain actions through the game, please let me know. I can't promise improvements, but I do promise to at least look into it
--- end of reply
I also checked the registration page, and indeed, the captcha is gone for now
I really love the game, it is the best thing i startedplaying in at least a year, and i imagine this dev also ending up on my list of devs i like to support.