In The Light Keeps Us Safe you play as the last remaining human survivor of an apocalyptic event in which mysterious, seemingly alien robots have wiped out human civilization. The rest of humanity has long since either been wiped out or "escaped into the Light" while you were hiding in a bunker, but now that your food has run out you're forced to explore the robot-infested surface for a means of survival.
It can best be summarized as a Spiritual Successor to Sir, You Are Being Hunted, only with a much more dark, serious tone, more simplified inventory management, and no weapons to fight back with. Instead, your character has access to a special flashlight with multiple light modes that can be used to overcome obstacles. The flashlight's abilities include a standard beam that temporarily disables proximity shock traps, a focused charger beam that powers doors and shuts down enemy energy orbs, a revealer beam that reveals invisible platforms and hidden enemies, and a dissolver beam that dissolves certain walls and energy field traps. Since you lack any offensive abilities to fight back against the robots, your survival options are limited to stealth, throwing bottles to distract enemies or draw them away, or running away.
This game provides examples of:
- Bad Moon Rising: There's a weird alien lattice structure enveloping the moon, indicating the scale of how much the machines have altered the world.
- Cosmic Deadline: It seems that quite a lot of the game's total content, including major new enemies and obstacles, are crammed into the last two levels.
- Darker and Edgier: The Light Keeps Us Safe is a lot darker and more serious than Sir, You Are Being Hunted; the game mostly takes place in dark night, robot design is menacing rather than comedic, and you can even find many mutilated human corpses amongst the bombed out remains of civilization.
- Downer Ending: The central goal of the game is to gather enough motes of light to power on the giant machine in the bunker so you can "escape into the light". When you finally accomplish this, your body collapses and some sort of energy is pulled out of your body while the female voice that's been guiding you the whole game starts repeating lines in a strange manner and becoming distorted. It's left unclear whether you've Ascended to a Higher Plane of Existence or if the Light was a trap all along. The fact the game ends with a quote from Dante's Inferno doesn't help confidence in your fate.
- The End of the World as We Know It: One of the last levels has a burned out, totally destroyed city still in flames as a backdrop. It's heavily implied the entire world is like this.
- Featureless Protagonist: The player character wears heavy winter clothing, including cloth face wrappings and goggles, which completely obscures their features.
- Silent Protagonist: The player character also doesn't vocalize at all.
- Implacable Man:
- Some of the later levels have a giant UFO in the sky that starts in the center of the map and slowly floats towards you position no matter where you go. If it reaches you, it'll start blasting you with shock beams until you're dead. It basically forces you to move through the area quickly and not delay in one spot for too long.
- Once it sees you, the invisible stalker will follow you throughout the level and can only be stunned temporarily by the correct beam on your flashlight.
- Kill All Humans: The machines seem to exist solely to wipe out humanity. No explanation as to their origin or motives is ever given.
- Resources Management Gameplay: It's been simplified from Sir, You are Being Hunted (all resources have a separate inventory slot, in contrast to the Grid Inventory Inventory Management Puzzle of Sir), but you still are reliant on resources (food, bandages, and distraction bottles) which you are able to carry a limited number of, and which have to be scavenged from the environment.
- Shock and Awe: The main weapon used by the robots is a close-to-medium range electrical arc attack.
- Sole Survivor: You play as what may very well be the last human on Earth, with everyone else having either been killed by the machines or "gone into the Light".
- Spider Tank: A sort of Giant Mook enemy type that moves more slowly that the regular floating squid robots, but packs a bigger punch.
- Spiritual Successor: The basic premise and game design are quite similar to Sir, You Are Being Hunted, only with a much greater focus on stealth and evasion (due to the absence of player weaponry), and a much more serious tone.
- Starfish Robots: The basic robots strongly resemble the Sentinels from The Matrix trilogy.
- Stealth-Based Game: Even more so than Sir, You Are Being Hunted, due to the inability to fight back against the robots.
- Weakened by the Light: While the flashlight can't be used offensively against most robots, there are a few specific enemies that can be temporarily neutralized with it. You can disable the Dalek-like proximity traps with the basic beam, the slow-moving heat-seeking black energy balls can be erased with the focus beam, and the invisible stalker can be stunned with the revealer beam.