Seems you were right, it was Amiga-only. But I was lucky and stumbled upon the homepage of the game's artwork designer and among lots of other stuff he got a free download of the full game there!
If anyone is interested, follow this link
http://www.edvardtoth.com/ and then go to Perihelion under "projects".
It comes in a .zip file including an emulator, so all you have to do it unpack it and run. I urge everyone who is into oldschool RPGs to give this one a try, it is truly different!