It doesn't seem like a link to the source code was an official part of the submission, but because it was easy to track down I had a play.
I'm not super sure what to do. I made some sort of potion and thought maybe I could drop it on the zombie, but that didn't seem to do anything. All of my other attempts to do stuff crashed the game with
thread 'Compute Task Pool (0)' panicked at 'not yet implemented', src/potion.rs:113:14
So I'm guessing it's just very unfinished?