Gears 4 has the distinction of being the darkest reveal of a high-profile game I can remember. There were whole portions of its runtime lit only by the world's weediest under-slung torch (I think the plot must focus on the Locust eating all of humanity's batteries or something).
Seemingly this is a design choice, because the first screenshots of the game follow suit - squint your eyes at these bad boys. There's certainly a reason to - the game's clearly continuing the series' tradition of chivvying the Unreal Engine forward into ever-more impressive territory, and this is looking like a more contained, horror-inflected game than previous instalments.
There's something interesting in the works at The Coalition - I just wish I could, like, see it.