Steven78 is the person, who posted the screenshot of the title screen, the script of codes and the description on NintendoAge. He lives in Netherlands and has a lot of prototypes of games. He even has games, that were never published or completed (such as the Pac world, Shadows Of The Wind...). Where did he got them? I'm not sure.
It was really hard to find his sites/adresses. I eventually found out, that this person has been silent since 2017 according to SMSpower page. A User named Bock tried to contact him in 2019, but he never got answers from him.
However, I found his account with the same name on BoomBoxery. He must be the same person, because in his introduction page, it says, that he lives in Netherlands. And on NintendoAge, it also says, that he lives there.
But unfortunately, he hasn’t been active since 2019. But I still tried to ask him. No answers.
I found the article on Retro Game Network, that mentions him. Not only his username, but also his real name. Stephen Jacobs.
I tried many combination with his user name, real name, location...The only other results from that is a bunch of accounts on Facebook with his real name. There are hundreds of them, but we don’t know how he looks like, or where he specifically lives on Netherlands (but according to his account on nesretro.com, he lives on Utrecht.) The last result is his account on nesretro.com as we mentioned before, but again, not active on it. So I think there's no way to contact him anymore.
If you don't understand, what I'm talking about, here's the Bubsy Bobcat Wiki page about Bubsy 3: https://bubsy.fandom.com/wiki/Bubsy_3