X-COM creator Julian Gollop discusses his most important games (2019)

I maintain that his best game was absolutely Chaos: The Battle of Wizards.

Although later creations were more popular it's that first one that really stands in my memory 40+ years later.

I guess it might be time to fire up an emulator and play again, as I do every couple of years:

https://torinak.com/qaop/play/chaos

Chaos Funk was a pretty good reworking of it.

That one you posted is pretty good until you get to casting a spell, and then they little keyboard sans-cursors and the lack of apparent touch control all goes wonky.