Bizarre adventure/RPG spin-off series Worlds of Ultima is now free to download on GOG.com.
Both games took place outside of the original Ultima games' Britannia setting, with The Savage Empire set in the "primitive and savage world of Eodon," while Martian Dreams took place in a Victorian era Mars. The latter also featured such historical figures as Nikola Tesla, Sigmund Freud, and H.G. Wells.
The GOG page for The Savage Empire described it as "A great starting point for people who are new to the world of Ultima."
Deus Ex and Disney Epic Mickey creator Warren Spector worked on Martian Dreams, though he had a cameo in both titles as Dr. Johann Spector. Check out his pixelated likeness in the screen below.