The color choice and subtle lighting effects really elevate the simplistic visuals. I like how the player character squishes and bounces.
Sound effects would really go a long way for providing better feedback. There were many times where I found one of the gold pieces in the dark but didn't realize it because there was no kind of feedback.
The meter for the -1 vision felt like it filled a little slowly. There were a lot of times where I was just waiting for it to fill up so I could use it more.