Poetic and atmospheric!
As you said earlier, you give the player crude visual idea of what the area might be. I guess, the colors are definitely help to set up tone. (For what, I guess, should give a tribute of appreciation both to you and Polyducks) They're just so vibrant, it's cool. Welp, until I explored dark areas, which seemed a bit off. Muddy? (Swampy) Personally, would have choose some different colors to have a contrast between lightest and darkest areas. Went on a jerk mode, ik you had to do it in just 3 hours, LMAO.
Good game overall!