Ghorpm: Nobody, really? This situation was first described in a book. A bestseller I might add.
I looked at your image soon after it was posted. It's certainly attractive, though oddly colored; I thought it might be the second Toejam and Earl at first. It's set on their homeworld and the landscape is alien and colorful. Then I noticed that the fish were dead. Blades of Exile is the only polluted river game I can remember, and it didn't seem like that, either. So I didn't guess. I'm easily lost.
edit:
Hmm, book-based games...
Those by Bram Stoker
Those by Jules Verne
The Witchers
Deathtrap Dungeon
I HAVE NO MOUTH
Unsure about Inquisitor
Anyway, don't take the above as guesses. If anyone can use the info to puzzle out your game, though, great!