Thank you for trying out my game. The player and boss were hand drawn. I think I understand what you want to say about precision, one of the crystals is kind of hidden and can't be reached easily.
I am planning to expand this game with more bosses and content.
What improvements would you like to see with the controls?
(This was made with the old input system in unity since the new one has given me issues with Webgl builds but will try it again in the future).