Played this for a few times and could finish it in around 4-5 attempts! Its a neat little platformer and integrates the theme very well. i liked the use of the arrow and the way these arrows were placed on the map to clearly indicate when you can go upside down. The movement also felt smooth especially jumping which is key in these kinds of games, so well done on that!
The artstyle was cute and clean, the character sprite was done well.
The game is easy enough but a bit unforgiving at times which is definitely a valid choice, though i would have liked if there were some checkpoints from where the player can restart after dying, so you need not play the initial parts over, but since its a short game, its not a big deal. I felt the combat can definitely be improved - right now what happens is that when you hit the enemy you by default get hit and lose HP. I dont know if it happens every time and what the reason is but for melee combat, i think you should definitely have some room between the player and the enemy for your weapon to give some room for error otherwise it feels a bit unfair.
Music went well with the gameplay, but felt it was a bit repetitive after a while. Sound effects were decent, but I felt there could have been more especially for the jump and the upside down turning - since these are ones which are key to the gameplay.
Overall i think it was a fun game and you have strong core elements of platform mechanics and the upside down element, with a little bit of polish would become a lot more fun. Well done :)