Thanks for playing :)
I wrote the AI, and it works on a few simple rules.
For AI pathfinding it's Depth First Search that sorts unvisited nodes by distance first, then by cost.
The AI has a target priority list that you can feed to him. I planned to have range units, and some other unit types, so the AI would target a specific group first. In the jam version it only targets closest though, but you can give him any object or array to target from.
For attacking the AI's goal is to attack his target, but if he won't be able to do it in this turn then he will go through the target priority list and find the first target he can attack along the way. (so in a sense the AI will decide whether to attack first and then move, or vice versa).