There are certainly limits to the spontaneity possible within a computer game, but the essential aesthetic of "combine two words to cast a spell" is actually something the Ultima CRPGs did years before Ars Magica existed.
A spellbuilding engine with similar flexibility to a Minecraft-style physics-building engine could be really fascinating.
Magicians in Ars Magica are not "adventurers" with a staff and a mantle. They act as independent and powerful heroes with their magical shelters, laboratories, agents, and assistants. Every magician also has ordinary talents, such as fencing or leadership qualities, which are not opposed to magic but complement it. At the beginning of the 10th, Ars Magica planned to make a video game, but the project did not raise the required amount. And people gradually started to switch to playing Diablo 2 . In general, if we compare the service of the game Diablo 2 Classes - Skills for all Characters in D2R | Yesgamers.com and the Ars Magica service, then Diablo is still more interesting.
I've been a fan of Ars Magica for many years, and I'm very sad that there is no PC game for it. The setting is perfect for an RPG, with its combination of magic and historical realism.
Master of Magic always seemed close, and a Master of Magic castle even made it onto the front of a 5th Ed book.
I see ( at least) two different ways a computer game of ArM could be done:
One is character based, where you design a magus, and go on adventures or interact with other magi/mundanes alternating with time in lab or library.
Another is covenant based, where you manage a covenant with magi and grogs, and send parties out on quests etc.
I'd play either one
I mostly see how the second varient could work. Something more akin to a sports team manager simulator could work with abstracted resolution.
The Baldur's gate or Elder Scroll type of game would be too open ended and too easy to break. Chucuking around Terram magic in annopen world would turn it into a weird Minecraft. Similarly an engine that would need to be able to model Mentem magic would be a huge undertaking.
With modern day language models, you could probably make a purely narrative, text-based game, a little like the 1980s The Hobbit, just an awful lot richer. I think it should work whatever is your main character, but it would take a bit of work to make a hybrid game incorporating both a language model and a mechanical model.
Not sure it would revive computer gaming as far as I am concerned, but for people who have not yet lost interest ...