The write-your-AI-to-fight-other-AIs concept is not a new idea, not a new idea at all.
In fact I think I remember playing a quite simple version, featuring a mere ShieldUp-Turn90°Right-Shoot-Move array of actions, as far as nearly 30 years ago.
If I recall, that one involved actual scripting, in...? So many years, who knows anymore.
I have seen the concept picked up a few times since, but was never satisfied with the execution.
One game, on psx, tried harder than many and despite failing terribly in the west, managed to get quite a following in Japan, well past its publishing date. I may be one of three people in Europe who have the original disc. But even It, fell short for me in many ways.
Point is, be it the technological limitations of the era, the hideously complicated UIs or the lack of multiplayer, none of these were the game I would have liked to play. So this is my attempt.