This is, perhaps, the most apocalyptic and non-survival-oriented RPG I've ever seen. Takes some cues from The Hateful Place, and a lot of inspiration from Silent Hill and Alan Wake (among others - the front page is pretty explicit about the inspirations). Just like it says on the tin: one day, the lights go out. All of them. No moon, no stars, no electricity - the only light available is via natural sources (like fire and the chemical reactions that allow glowsticks to work). 1/3 of the people in the world went insane immediately, violently so, and tried to kill everyone around them with degrees of success, but this problem self-corrects soon enough. There are other things in the darkness, though, and they're much better at killing people than people are at killing them. That's not even touching on the environmental hazards, too...why are the squirrels looking at you so hungrily?
The game is harsh, with death and maiming coming very easily and recovery slow if at all. Starvation and dehydration are constant concerns, rest is a precious commodity that is difficult to obtain, and the Dark is inside you as well as outside you in the form of recurrent nightmares and barely suppressed insanity. You start with one, and can easily get more with bad rolls. You check when you meet a new type of monster for the first time, and if you make that roll you don't have to worry about rolling again thereafter for that type of creature. Mundane horrors (like swarming roaches or bloodthirsty skitters of squirrels) don't inspire a check at all.
PCs are fairly normal humans, but there are a smattering of supernatural abillities available at character creation in the vein of sense/hide/manipulate at great investment in points. As said previously, the Dark is inside you too, and you can potentially make use of it. Other, more potent supernatural powers are available, but only with experience - good luck surviving to get it, BTW. The most promising one, Alchemy (technically a skill rather than a power, using parts of monsters and the odd fungi and other growths that are beginning to supplant normal plant life in the smothering darkness to be able to make useful substances with supernatural or at least useful properties), is sadly not fleshed out at all and waits for a supplement to take advantage of it.
Monsters are tied to a Darkness Level, somewhat similar to a Fear Level from Deadlands, ranging from 1 to 9. Monster level is tied to Darkness level, so less than 3 means normal threats like hungry packs of small animals and the like. It takes a Darkness Level of 3 for actual monsters to beging spawning, and a Darkness Level of 4 to get a Guardian class monster (a boss-type creature) to spawn. There are references to Dominators as the next stage up from a Guardian (big and lethal), but no examples given nor any indication as to how they spawn. In the event that you can kill a Guardian, it resets that area to Darkness Level 1, leaving it (somewhat) safer to rest or scavenge in for a while. PCs don't know the Darkness Level of a given area, and can't find out without successful Sense Dark skill checks. Darkness level is variable, but the rise and fall of it is influenced by the presence or absence of people. This means permanent camps and large settlements are right out, and getting much larger than your group of PCs is begging for trouble on multiple levels. Oh, and gunfire can and will draw the attention of monsters from a great distance, and potentially draw in adds to an already existing encounter.
In terms of monsters, there's not a lot on display, but what is there is promising. There's basic lurking horrors that are more dangerous in numbers than solo (on the cover, in the back), spidery things that set up shop in buildings and lure prey to them, that charming fellow centered on the cover who is a filed-off-the-serial-numbers Pyramid Head, and a few others. There's also mundane hazards in the form of roach swarms (enlarged and given acidic saliva by the Dark - not directly dangerous to your players, but will destroy supplies and make resting even more difficult) and "squirrels". I put that last part in quotation marks because it's something of a catch-all for wildlife that has gone bad due to the Dark and has decided that humans are on the menu. "Squirrels" lurk around the edges of a light source, and while they don't attack groups a lone traveler will be jumped as soon as enough of them gather to feel confident in attacking. Examples of "squirrels" are squirrels, pigeons, and of all things...Deer. The mechanics are set up for small swarmy critters, BTW, so good luck getting the image of deer dogpiling someone out of your head...But more to the point, it's pleasant to see more abstract and squishy horrors on display than a standard pastiche of vampires/werewolves/etc etc etc.
All in all, an interesting game. Biggest critique would be that it's too lethal as things stand. I understand and appreciate the nature of the setting they're going for - this isn't post-apocalyptic, this is the apocalypse, and it's not supposed to be easy to survive. That being said, there's just way too much stacked against players between the need for light sources ("you will be eaten by a grue" if you don't have one, what do you think the "squirrels" are for?), great difficulty to rest and heal, and other mechanics. It'd be great for a one-shot or several day convention scenario where you don't have long-term aspirations for the game, not so much beyond that without a fair amount of setting and rules tweaking. Still, this has some great ideas and makes for excellent inspiration. Keep an eye on it.