Adam, If you want your game to have a dark look and still have interesting lighting play with lighting color and placement. If you change the color of the light so it is darker you will have a darker lit area but you will still show detail. And where you want items to display more clearly use a brighter light, meaning a brighter color closer to white than black. Try using a variety of lights and darks. And you can change the light range too. If you want to just light up an object brighter set the light range to circle around it. You can see the light range by hovering the cursor over the light entity in the editor. Keep in mind the light fades where the circle ends so make it a little bigger to light an object. And try to use static lights because dynamic lights will slow down your scene.
It takes a while to get the lighting right because you have to keep adjusting and testing the level but it can really help the look of your game.
That is what I have found so far. I hope that helps you. I am glad to see you are not getting discouraged. Keep going, you will get it.
Dennis The Frogman
www.3dfrog.com