I just watched the ending cut scene. Brilliant game. One of the best games I have played in a long time. Some comments:
The sense of exploring uncharted territory is really strong in the game. The absence of ridiculous augmented reality waypoints helps with this, while excellent environmental cues and lighting mitigate disorientation. Optional areas actually felt ... optional, with an admirable lack of signposting and some nice mutant ambushes thrown in to make things tense.
Despite the focus on exploring at your own pace, obsessing over weapon customizations and stealthing, the sense of forward momentum in the game is palpable. Stealth encounters against humans seem to make up about half of the game, but those bits are expertly mixed with bits where listen to conversations in inhabited areas, bits where you traverse and explore the surface, and horror bits both on the surface and underground.
The success of the stealth system seems like a "less is more" thing. Everything is solvable by messing with light sources, stalking enemies and seizing opportunities when enemies split up, while silenced weapons increase the player agency if you are prepared to get blood on your hands. All of this is designed without quick save in mind, which is always a bonus.
I first tried to go for the no kill achievement, but even as a do-gooder ranger, some opportunities with silenced weapons felt so natural (and sometimes deserved) that I had to take them. While other shooters often make you feel like a deranged mass murderer, Last Light allows you to be a very special brand of psychopath who doesn't kill indiscriminately. This might seem a bit silly, but I thought that it added to the immersion of being an elite warrior in a post apocalyptic world.
The sense of being present in the world is just ... fantastic. Some Starbreeze/DICE quality immersion at display in the game. Minimal HUD, condensation inside the gas mask, dirt that you have to wipe off on the outside, hearing yourself gasping for air, special animations when you are jumped by monsters and stressing over air filters and cracks in the gas mask are just the tip of the iceberg.
I hope that the developer gets the recognition and sales they deserve for this game.