Made up a simple single-source lighting demo that can easily tweak gradient strength or light radius to achieve different kinds of lighting. RIght now it's displaying the kind of lighting seen on the 2nd pic below. It uses interface objects that stay in place so you don't have to cover your entire map with darkness objects, only everything within the initial starting screen space. Proximity detection wasn't available for interface objects but you can extract x/y of the tracker object and filter the result to get the same effect.
The radius could also be changed to simulate your lantern running out of fuel, and the darkness itself could run on a timer to fade in/out during daytime if you had day/night cycles.
Here's some screens showing different gradients.
Here's a demo using raycast to produce shadows. These shadow objects are always aimed to the player's location, a hit means there is vision from its point to the player, so they are set to 0 alpha, and a miss means there is an obstruction from its point to the player, so they are set to 100 alpha. Right now they don't follow or track the player's location, for example if you left the location in the demo you would leave the shadows behind as well. The goal is to make them follow the player eventually and perhaps try combining with the gradient light above.
WASD for movement. You can press 1,2,3 to change the texture from lighter to darker shadows. The UP arrow key increases sight radius, DOWN decreases.