Artificial intelligence for games in Unity

The "False Knight" boss in Hollow Night does not use advanced AI such as machine learning or deep learning, which are learning AI. You can decorate bosses ' patterns over time in Hollow Night, such as when he will attack in this way or jump or hit the nail on both sides of the ground, and your brain memorizes these patterns over time. So False Knight uses a simple AI called: finite state machine. It's a good start to start studying.

What this does that mean? That it has its predefined attacks for example:

1. jump attack and hit nail in the character's direction.
2. simple nail attack.
3. nail attack with chao power.
4. nail attack in the center of both sides.

Basically the finite state machine will tell the conditions under which it will perform each attack. Example of conditions:

1. Player is close.
2. plays is far away.
3. Player is no air.

A representation in C# could be:

public enum BossStateIA
{
     ExecutandoAcao,
     RequerAcao
}

public enum BossAcao
{
     Nenhuma,
     AtaqueSimples,
     AtaquePulo,
     AtaqueEspecial
}

public class Boss
{
     private BossStateIA State;
     private Acao AcaoAtual;

     private Acao IA()
     {
         Acao acao;

         //Define a próxima ação a ser feita em uma máquina de estados
         //finitas, simplesmente use ifs, and e or. Se o personagem 
         //está perto, longe, pouca vida ets.

         return acao;
     }

     public void Update()
     {
         if (State == BossStateIA.RequerAcao)
         {
             AcaoAtual = IA();
             State = BossStateIA.ExecutandoAcao;
         }

         //Executa o código de acordo com a ação atual.
         //No final da ação defina a variável State para RequerAcao.
     }
}

Artificial intelligence for games is a series of patterns performing for certain actions, it is not worth using machine-learning or deep-learning, I would do something like this

bool acao = false;

void Update(){
  if(!acao && Vector3.Distance(transform.position, player.position) < 5){
    Atacar();
    acao = true;
  }else if(!acao && Vector3.Distance(transform.position, player.position) > 50){
    AvançarNoPlayer();
    acao = true;
  }
}

void Atacar(){
 // Atacar
 acao = false; 
}

void AvançarNoPlayer(){
 // AvançarNoPlayer
 acao = false; 
}

And so goes