What a feedback.
You said everything I wanted to write down.
Tutorials:
Play other games. What are the tutorial telling them ? You don’t need to tell them everything.
Slower pace and before telling them something new, let them try out first.
Level pace:
Make it longer… combine it with a small platform set, before a hard boss or enemy.
Introduce the player to easy enemies to try out different attacks. let them die in 1 or 2 hits.
The first boss should have an easy attack and movement variation.
let the player observe and let them try out there own playstyle.