You can get the player’s position with the “mySpirte x” and “mySprite y” blocks.
Everything the enemies and bosses do in the game is entirely possible without an extension. But I used sprite utilities extension to do most of that. It has an “get angle from one sprite to another” block. It also allows you to make “on game update loops” for specific sprites.
It takes some practice to make decent enemy AI, this is not my first attempt. Here is a post I made with a simple example: How to make AI - #7 by Bifrosty