Most people looks for good ideas with poor game development, so we must judge the idea. In your case, you have done a poor idea with high development, so I can only dudge that.
*Pixel art is awesome
*Animations also very good
*I like little deatils like "red flash" when hits
Now my bad feelings. Obviously is very very hard to polish this kind of game in 72 h, so don't take care my opinions:
*Make the background image bigger and use a little side scrolling. It will improve the depth feel a lot
*I think you have selected the controls in order to play by one hand. Try to separate them for two hand. For example:
A/B - move
Space - jump
U - attack
I - block
*Make the bottom terrain darker. I mean, you must increase the color/light difference between the platforms where you can walk and the terrain where you fall down.
*The attack-timing is wrong. I mean, the "red flash" (and health fall) happens at same time than attack animation starts. The feeling is wrong. You must trigger the red flash when the swords collide with the character, or 0.3 seconds from the beginning of animation. If you solve this, you will have a little time to block the enemy attack before be injured.
*The combat is like two kids playing: block-attack-block-attack-block... The easiest way to solve it is to randomize the enemy attacks. Moreover, you can reduce the attack probability of the enemy when you are blocking, so it encoureges you to attack.
*Limit the number of jumps in the air to 1. He's not Superman.
*If you jump to a vertical wall you should fall down. He's not Spiderman ;)
I repeat, you have done a big work, but it's very very very hard to do an action game like yours. By this way, it is much more easy to think a good idea with simple implementation.