Hi, thanks for your feedback!
The lack of communication in the cooldown is a design choice, as we wanted to keep controls simple our solution was a fixed interval attack (inspired by Vampire Survivors). Edit: Also, we chose to keep the UI minimal in favour of immersion.
About the bosses, what you're experiencing seems to be a bug, maybe introduced because most of the behaviour of the enemies is not shared and has to be set manually by the designer. Maybe he forgot. We will look forward to fixing it in a post-jam version.
The rotate around mechanic was to add a bit of depth to the combat, we liked it this way, as you rotate with your mouse to aim towards the enemies, this mechanic felt natural to us.
Thank you for your honest review! Genuine feedback is always appreciated :)