I quite like this! This is a fun take on the COD Zombies/wave survival genre and I hope you continue to run with the theme. A suggestion - perhaps your fists could be used for a backup weapon where you waggle the mouse to do a slight bit of damage when you are in a pinch?
I really like the movement as well, very different to what I'm used to and it's quite cool!
A couple things to maybe improve:
AI (you mentioned it in the description but the AI got stuck in a conga line and couldn't move)
Weapon balancing (I think the shotguns are a bit overpowered considering they spawn frequently, shoot pretty accurately, shoot 3 pellets, and also can chain kill).
I hope you continue to develop this idea!