The Prototype campaign is the first ever campaign that I made for the Left 4 Dead Series. Somewhat confusingly named, initially it was just going to be called "Prototype".
To the degree that this campaign uses forced zombie-spawning to spawn many, many, many more zombies than are normally present in the game, the initial Prototype was that much worse
than the published iteration. It was unplayable in multiplayer because it would simply crash. So I rebuilt the whole campaign, and called it Prototype Mk2 (read "Mark 2") to differentiate
it. I figured I would simply rename it when it came time to publish it, but when Source Engine compiles it builds several files with interconnected dependencies, all of which were now
referring to a "Prototype_Mk2", and when I tried to rename it, everything broke. So, being very new to Source Engine, I just decided to leave it and ship it with a slightly awkward name.
But Prototype Mk2 was built for the first Left 4 Dead and when I published it, I got a ton of messages asking if I couldn't put it on Left 4 Dead 2, where the modding scene
was so much more robust. So I rebuilt it a second time, and I guess intuitively it seemed wrong to name the version for L4D2 Prototype 1 when L4D1 had Prototype 2, so I named this one
Prototype Mk 3.
It doesn't look as much like Tron as I had initially hoped it would, and some of the things I wanted to do with it I was never able to fully realize. It
has some problems with balance, you know, like you'd expect from a designer's first time out, though when I built it I wanted it to be challenging even for veteran L4D players. Many
people have told me that it is murder on the eyes, but I don't think there's another campaign that comes close to this level of sci-fi aesthetic in the workshop, even a decade
later.
It's blinding. It's hard. And I'm proud of it.