Thanks for the detailed feedback, we're planning on reworking a lot of things in its final release. I felt the worm boss was relatively balanced as there isn't that much restriction in mobility; you can move away from the worm and if he's closing in you are able to jump over him and move away. That being said hitboxes are an issue right now and I am currently working on improving them. Restarting as well I felt was generally fine as the path to the boss itself is very short and there are no enemies to worry about leading up to it.
We'll be working much more on content and picking up the pace. Thanks for the feedback once again.