Feneric has recently released a new game called Minima. It's inspired by Ultima and is intended to recreate the feel of playing RPGs on 8-bit Commodore computers, but it's a completely new game and is fully playable. Some people have reportedly already been able to beat it.
From the Minima GitHub page: "Minima is an adventure RPG in the style of the older Ultima games as played on the Commodore 8-bit computers. Just like the original Ultima games, it includes a world view, enterable towns, and 3D dungeon displays. It also features graphics, sound effects, and music that should help one recollect those classics. More importantly, it is a fully playable (and winnable) game with its own backstory, plot, setting, and characters."
If you'd like to learn more, or play it, check out the following links: