Very nice theme and graphics. Movement is solid.
The pushing of crates feels a bit random, sometimes you have to be on top half to push forward sometimes bottom part, maybe make this more consistent.
Combat also looks great but its hard to determine whats going on and the timings of attacks. I kept stepping back from the skeleton so he never hit me. Did spend some time unarmed trying to fight him without a single hit... But later figured out what I was missing, so that's on me I guess.
The encounter of the rat broke the game as you said, but I did not find any pause button, and it's usually ESC but that did nothing.