The health bars are positioned by a vertex shader, so can easily be scaled up or moved. Right now I'm using a hardcoded vertical offset: https://github.com/ChristopherBiscardi/bevy-jam-7/blob/6e8d26bb6f94bb62d43146b08... . The player's health bar should really be in screenspace UI as well.
I agree audio would've added a lot. Alas I ran out of time for that and damage indicators, etc. I think both small damage numbers and a "hit flash" shader would've helped.