I would like the FOV to essentially remain the same, computing within a circle defined by the creature's sightRadius. The current algorithm doesn't work well with trees. Or anything other than well defined walls, really.

Walls and such we can adjust with a different background, to make them stand out from the rest of the tiles. I'm sure we can make more of these kind of improvements on other tiles to make the game more clear to the player where he should go and easier to find the objects he is looking for.