Lot of things to improve but you got a start and you got some system workings: movement, camera, health, attack,menu, enemy following player.

The camera: Your camera works, but with the way you game works you will probably need to add a rotation on it at some point.

You should add some more animation depending of the action, like idle or attack for exemple, it's hard to know if the player is attacking or doing nothing, and add a rotation depending on where you go, the player need some feedback on his actions.

Your attack need some range, actually you can't hit without getting hit back, you have exactly the same range of the enemies, making impossible to win in a normal way, you could also add some knock back.

I killed the boss. Using secrets gamer special techniques (blocking the boss and wait for the heal to regen..), you should add a button to quit at the end.

You can walk in the void, player should fall.

Fun fact, you can walk on the boss.

This is very good, and will be even better if you keep updating it. 

Looks like a good start, based on the gameplay I feel like being able to rotate the camera around the player would do good. A red glow or something when hurting players or enemies would be good too. You should continue to update it after the jam is over, it would be cool to see what you turn it into!

Nice idea, but a lot of things to work on. Maybe you could find some attack animations and idle animation for enemies and main character. The boss seems impossible to kill, I tried a few times and failed. I enjoyed movement and main menu design, it was fancy. Good luck in future projects!