This is cool. Very atmospheric and the core mechanic of using your own dead bodies is innovative and thematically fitting. A few notes:
The cooldowns are infuriating and it doesn't seem like they add anything specific to the game. If you intend to keep them, maybe make them shorter and make them reset on death. It might also make more sense if they filled up instead of running down.
I wish i could punt my dead bodies around and use them as projectiles. I got to a point my first run where i had a half dozen bodies between me and the wizard. Would have been great to be able to do that.