Finished playing through it last night. The atmosphere from the artwork is really enjoyable, you did a fantastic job!
With pixel art in modern day games, I've seen a lot of people make art that is really neat for GBC, but not necessarily practical for actually playing. I played this on an original, non-modded GBC and it was a great experience! Everything looked nice while still being very readable.
PS - the style to me feels like if Capcom never moved on to the GBA and instead made Minish Cap on the GBC