It is pitch dark. You are likely to be eaten by a Grue.
https://www.youtube.com/watch?v=4nigRT2KmCE
Kill dragon
With what? Your bare hands?
Yes
Congratulations! You have just vanquished a dragon with your bare hands!
This was a childhood highlight moment for me. I'd been playing Adventure for ages just having fun without realizing there was a huge world beyond the snake.