In case you still wonder why your lights and textures are kinda dark:
You probably have, as all people, set your device to automatic brightness. This is rather dark for games.
You can try this snippet:
WindowManager.LayoutParams lp = getWindow().getAttributes();
lp.screenBrightness = 1.0; // or whatever
getWindow().setAttributes(lp);
to override brightness settings.
Not all devices or users will like that, but it may be worth a try. In Armada, I set the brightness to 0.85 per default, but the user can deactivate the override.