This is probably a little late, but I wanted to note here that it looks like the Gold edition is more than just achievements.
I bought the game on GoG and had a very difficult time getting DOSBox to not crash on the title screen. When it worked at all it stuttered horribly. After playing with the settings a bunch, I bought the Gold version on steam, and it launched without dosbox and I had no problems running it. I know Dotemu did some update work to make the game run on iOS, so perhaps that work was brought over to the Gold version.
I also see that the Gold edition says it has a new more intuitive UI and inventory, a new hints system, in addition to achievements.