A possible concise summary is:
The text is a transcript of a video game commentary by four players who are playing Left 4 Dead, a zombie survival game. The players are Mark, Jack, Wade and Bob. They are trying to escape from a horde of zombies and reach a safe room or a plane. They also have to carry a gnome with them for some reason. Mark is very aggressive and reckless, often running ahead and leaving his teammates behind. He also claims to be the best player and boasts about his kills and stats. Jack, Wade and Bob are more cooperative and supportive, but they also get into trouble and die frequently. They often blame Mark for his actions or mock him for his failures. The commentary is full of swearing, screaming, laughing and joking. The players have a lot of fun and frustration while playing the game.
Some possible facts extracted from the text are:
1. The text is a transcript of a video game playthrough of Left 4 Dead 2, a cooperative first-person shooter game.
2. The players are Mark, Jack, Wade and Bob, who are YouTube content creators and friends.
3. The players are using a mutator called Healing Gnome, which replaces the first aid kits with a garden gnome that heals them when they hold it.
4. The players are trying to survive and escape from hordes of zombies and special infected, such as hunters, smokers, boomers, chargers and tanks.
5. The players are often arguing, joking, blaming and teasing each other for their actions and mistakes in the game.
6. The text covers three levels of the game: Dead Air, Crash Course and Dead Center.