I'm curious about if everything is supposed to look like it's glowing because I don't think it's working too well. Perhaps the artist could get some critique on it somewhere.

I also forgot Cave Story when mentioning retro-style games that look great. It conveys the atmosphere very well. I think pixel art might help with the somewhat muddy feel of the graphics imo. And as seen here there can be little character portraits that convey a lot and are probably faster to do than realism.