Managed to beat this on my first playthrough! Once I figured out the targeting system, I felt so OP haha.
It could do with being a bit more challenging; but not through just buffing the boss as that could very quickly become unachievable. Maybe the boss could have had different moves? Like the boss does a grand sweep, and you having a team-wide invulnerability that you could use to counter?
All in all, was a fun game. And I really really enjoyed the sfx, as well as the boss animations. Great job with this!