Well atm I don't got the time to try to edit things, but here's an idea for someone who has the time.

Some kind've light or something protruding from the top of enemies heads, so that you can see em from further away. Like in snow you could see them them(the thing sticking out) even if they're behind a wall.

If it's possible then gogogogo! if not please tell me so I won't try it in the future >.>