This is cute! The sounds and visuals are delightful. The 3D definitely helps with the usual problems with depth that 2D beat-'em-ups have.
Some of this feedback is based on taking this prototype at face value as a slice of what you'd like your full game to be, including Beat's design and weapons. Both of which are neat but I feel like you could expand on the moveset Beat has with his sword and shield.
What about making one attack button Beat's sword and the other attack button Beat's shield? Both could have different properties for different types of enemies, or perhaps the shield is good for lighter but weaker attacks that can open enemies up while protecting Beat whereas the sword is good when you want to commit to an attack. I've been thinking lately that there aren't really any dedicated sword-and-shield games with an expansive moveset that factors both items into account and I think there's a lot of design space for you to explore here, especially when you include mixing the attack buttons and holding the buttons down.
I think games have long since passed the point where double tapping a movement key is necessary. If this is staying a PC game, then you definitely have more than enough buttons to make one of them a sprinting button. Or just making sprinting the default movement speed.
So that's all I've got so far. Keep up the good work!