Hey there was a survival horror game from a few years back (I forgot what it was called) that was in top down. It had a cone of vision mechanic that would let you see under trees and stuff the cone was shined on. Then at night without any light you could only see with the cone. You should add that mechanic to the game. It would make it quicker and easier to pick up items under trees, and make torches more valuable at night. You could also make it so the cone can be increased in your upgrade tree, and have it shorten at low health and low heat. As for multiplayer you could do 1 of 3 things with it. You could make it so you can't see other player's cones at all, or make it so you can see their cones but not see under trees with them, or you could also make it so you can see their cones and see under trees with them. I think this is a really good top down game mechanic that you should include in the game.