Really cool concept! I love how the fire has two radii, the "light" radius and the "dark/inverted". Super clear and clean way to represent 2 light levels. I had a great emergent moment where I panicked and dropped my ax somewhere and the fired died down so I had to use the torch to go out and find it again.
Minor UX quibble: Why X and C? Surely Z and X make more sense?
Slightly larger UX quibble: I had a hard time determining how far my throw was going to reach. The two ways I could see fixing this is having a projected landing spot when you hold down the throw button and execute the throw upon release. Or you could just make the throw more forgiving when you throw a log onto the fire ;)