You can learn more about these images and their backgrounds by watching the Valve News Network video about the screenshots and the investigation that went into finding them. Sadly, these purported Left 4 Dead 3 screenshots give us a look at a game that would have been welcomed by PC gamers around the world. It’s clear that these were taken from something that was very much a work-in-progress, especially since the skybox looks like it doesn’t quite have the right level of detail for a retail release. Some areas are dark and claustrophobic, but there are also plenty of wide-open spaces that would have been perfect for a fight against a Tank or similarly-large enemy.
The images show off a desert map with varying kinds of scenery. Instead, one gets the impression that these Left 4 Dead 3 screenshots show off a linear level that was intended for a different kind of gameplay. While this might lead one to think that this is indeed a map from that game, a more careful examination of the map geometry shows that it is lacking many elements that would be necessary for a multiplayer game. At first glance, the Imgur album of the screenshots looks not all that different from a Counter-Strike map.
