I like the pixel art for the little characters, but the environments are not good looking. I also don't feel the music you chose to use was very fitting to the game.
I understand you said you've made this in one week, but I don't understand your decision to not have the player's health refill after dying. He revives with 1 health, and then every single time you take damage you have to watch him fall over and be stuck for a moment until he revives. With 1 health. He also doesn't even get invincibility frames when he revives. When enemies were over my body, I couldn't escape unless I was mashing the jump and dodge buttons (somehow this allowed me to take priority and escape their hit boxes with a jumping roll dodge.) You could have had the enemies move away from his body to give the player momentary breathing room after 'dying', or giving him invincibility frames. If there isn't even a punishment for death (like the game ending, etc.) then you should have just had the health refill upon a 'revive' in your demo.
With enough work this could be made into something interesting, but as it is I honestly feel it really needs a lot of work to get there.