Really like the presentation and the atmosphere both the music and lighting provide ^^
Gameplay wise the character feels nice and responsive, and the melee range is clearly defined with that big slash effect, i also like the fact that you made the damage numbers pop up for every attack.
The only small issue i encountered was with the double jump that seemed a bit inconsistent with the second jump's height, there was one jump in particular where i had to try multiple times to climb up and only managed to reach the upper platform by luck, i feel that some of the double jump platform heights should be just a tad bit lower to fix this.
Despite that it's a cool game and i had fun playing it, i didn't go all that far cause i lost a bit of health trying to damage boost up that difficult jump, so when i reached the boss he destroyed me almost instantly haha :p
Anyway, solid entry, and keep up the good work if you intend to keep working on it :)