Thx for the feedback ye i think it need screen shake when you are hit i tried to make it visible by making the player shake and the hearts pulls but i guess thats not enough. And the boss movement is simple just pick a random number for the x and y positions and then glide the boss towards those positions(you can have an invisible sprite that can be used as a pointer that the boss moves towards as well. And if u like any ideas i would love to see how you use them so good luck on your game.
code for player movement: 