I've played it yesterday and it's extreme fire, I love this! The music compliments the action and visuals extremely well and gameplay is very engaging.
I don't mind the boss being tanky as there is currently only one, but if the game is going for more bosses I'd suggest having more variety in our attacks, the boss has many and it's fine but we're feeling some repetitivity in our attack.
I had a lot of fun, thank you :D