«Left 4 Dead Afterthoughts». 1up.com. Archivado desde el original el 18 de enero de 2016. Consultado el 19 de enero de 2009. «We actually started out with a single, huge city design with a great many routes for the survivors to take to reach the extraction point. As we began to playtest in this zombie city, we immediately discovered that having that much choice combined with the chaos of zombie hordes made for frustrated and paralyzed survivor teams».
Kojima, Hideo (14 de enero de 2009). «Kojima: «Maybe I Should Quit Being Japanese»». 1UP.com. Archivado desde el original el 22 de enero de 2009. Consultado el 19 de enero de 2009. «There are games everyone can play—maybe calling them 'kids' games' would be inappropriate—but there's also a deep base of core titles made with movie-industry people that explore the depths of hi-def. I'm addicted to Left 4 Dead right now, but people say to me that that game would never work in Japan.»
Newell, Gabe (21 de noviembre de 2008). «Gabe Newell Writes for Edge». Edge. Archivado desde el original el 9 de septiembre de 2012. Consultado el 22 de noviembre de 2008. «The events are trying to give them a sense of narrative. We look at sequences of events and try to take what their actions are to generate new sequences. If they've been particularly challenged by one kind of creature then we can use that information to make decisions about how we use that creature in subsequent encounters. This is what makes procedural narrative more of a story-telling device than, say, a simple difficulty mechanism.».
«Left 4 Dead 2 Interview». eurogamer.net. 3 de julio de 2009. Consultado el 5 de julio de 2009. «The AI director—I don't want to say it fell out of Half-Life 2, but it was definitely a jumping-off point of stuff we did in Half-Life 2, particularly Episode 2. There are a couple of key battles where the number of Combine, and where they come at you from, uses something like that. It's much cruder than what we accomplished with Left 4 Dead, but there was some of that there».
«Left 4 Dead Preview». Game.co.uk. 15 de octubre de 2008. Consultado el 26 de noviembre de 2008. «As with the best horror flicks, the back-story is left deliberately ambiguous».
«Left 4 Dead Review». Game Informer. 17 de noviembre de 2008. Consultado el 9 de febrero de 2015. «The amazing level designs will remind you of every zombie movie ever made».
Ocampo, Jason (17 de noviembre de 2008). «Left 4 Dead Review». IGN. Consultado el 11 de agosto de 2009. «Left 4 Dead is a game that venerates zombie movies throughout the ages, from George A. Romero's Dawn of the Dead to Danny Boyle's 28 Days Later».
«Left 4 Dead, Team Fortress 2, and Valve». ign.com. 5 de diciembre de 2008. Consultado el 26 de noviembre de 2008. «Yet it also features four distinct survivors who convey an incredible amount of emotion through their facial animations and the rich amount of voice acting. There's Bill, the grizzled old veteran; Francis, the tough biker; Louis, the everyday dude; and Zoey, the college girl. They're so memorable that you can hear their voices in your mind as clear as day».
«Interview: Valve's Doug Lombardi». Joystiq. 3 de julio de 2009. Archivado desde el original el 3 de septiembre de 2009. Consultado el 14 de julio de 2009. «The things that are happening, all the shit that is hitting the fan and turning everyone into mutant zombies, has gone much bigger than just Pennsylvania, which is where the original game was loosely set.».
Newell, Gabe (21 de noviembre de 2008). «Gabe Newell Writes for Edge». Edge. Archivado desde el original el 9 de septiembre de 2012. Consultado el 22 de noviembre de 2008. «The events are trying to give them a sense of narrative. We look at sequences of events and try to take what their actions are to generate new sequences. If they've been particularly challenged by one kind of creature then we can use that information to make decisions about how we use that creature in subsequent encounters. This is what makes procedural narrative more of a story-telling device than, say, a simple difficulty mechanism.».
«Eight Hands-on: Left 4 Dead Impressions». Rock, Paper, Shotgun. 4 de noviembre de 2008. Consultado el 23 de noviembre de 2008. «Over breakfast yesterday– before playing– we were talking about different takes on the zombie game that we'd like to see. One which didn't come up is one which Left 4 Dead grasps completely– its inherent perverseness. Now, it's a constant internet thing to discuss what you'd do in a Zombie Invasion, the implication being that you're smarter than anyone else. Which is fine... but that's not how the genre works».
Eddy, Andy (17 de noviembre de 2008). «Left 4 Dead Review (Xbox 360)». TeamXbox. Archivado desde el original el 23 de marzo de 2009. Consultado el 18 de noviembre de 2008. «The motion-capture animation that makes up the varied zombie behavior is incredibly good, with the visuals peaking when a rushing gray-black mass of zombies are climbing up, over and through the terrain to get at you(...) On the other hand, it's irritating when you come into a room and see an enraged zombie clipping through from the other side of a wall or door».
«Left 4 Dead Review». Examiner.com. 17 de noviembre de 2008. Archivado desde el original el 4 de junio de 2009. Consultado el 23 de noviembre de 2008. «First and foremost, it's probably the most faithful video incarnation of the zombie genre that fans have ever been treated to. Yes, even better than Resident Evil 4».
Erik Johnson (5 de diciembre de 2008). «Re: hlds Digest, Vol 10, Issue 13». Valve Corporation. Archivado desde el original el 12 de enero de 2009. Consultado el 9 de diciembre de 2008. «We're currently hosting about 5,000 game servers for Left 4 Dead on the PC.»
«Interview: Valve's Doug Lombardi». Joystiq. 3 de julio de 2009. Archivado desde el original el 3 de septiembre de 2009. Consultado el 14 de julio de 2009. «The things that are happening, all the shit that is hitting the fan and turning everyone into mutant zombies, has gone much bigger than just Pennsylvania, which is where the original game was loosely set.».
«Left 4 Dead Afterthoughts». 1up.com. Archivado desde el original el 18 de enero de 2016. Consultado el 19 de enero de 2009. «We actually started out with a single, huge city design with a great many routes for the survivors to take to reach the extraction point. As we began to playtest in this zombie city, we immediately discovered that having that much choice combined with the chaos of zombie hordes made for frustrated and paralyzed survivor teams».
Erik Johnson (5 de diciembre de 2008). «Re: hlds Digest, Vol 10, Issue 13». Valve Corporation. Archivado desde el original el 12 de enero de 2009. Consultado el 9 de diciembre de 2008. «We're currently hosting about 5,000 game servers for Left 4 Dead on the PC.»
Eddy, Andy (17 de noviembre de 2008). «Left 4 Dead Review (Xbox 360)». TeamXbox. Archivado desde el original el 23 de marzo de 2009. Consultado el 18 de noviembre de 2008. «The motion-capture animation that makes up the varied zombie behavior is incredibly good, with the visuals peaking when a rushing gray-black mass of zombies are climbing up, over and through the terrain to get at you(...) On the other hand, it's irritating when you come into a room and see an enraged zombie clipping through from the other side of a wall or door».
«Left 4 Dead Review». Examiner.com. 17 de noviembre de 2008. Archivado desde el original el 4 de junio de 2009. Consultado el 23 de noviembre de 2008. «First and foremost, it's probably the most faithful video incarnation of the zombie genre that fans have ever been treated to. Yes, even better than Resident Evil 4».
Kojima, Hideo (14 de enero de 2009). «Kojima: «Maybe I Should Quit Being Japanese»». 1UP.com. Archivado desde el original el 22 de enero de 2009. Consultado el 19 de enero de 2009. «There are games everyone can play—maybe calling them 'kids' games' would be inappropriate—but there's also a deep base of core titles made with movie-industry people that explore the depths of hi-def. I'm addicted to Left 4 Dead right now, but people say to me that that game would never work in Japan.»
