Imagine the events of Portal taking place somewhere near the timeframe of L4D. Chell has escaped (supposedly), Glados, as you know her, is destroyed (or at the very least damaged), one of the enrichment center areas is showing severe structural damage, and now, in the outside world, a zombie apocolypse has descended.
Aperture Science, while now more or less a ghost town, is one of the few remaining places that was built to be self sustaining. If it doesnt have a means for the Survivors to escape, it would prove an excellent place for them to barricade themselves in. With power fluctuating, and security systems working intermittenly, some of the Infected have found their way in.
/end basic synopsis
Basically, my aim is to provide some elements of Portal (aka being trapped in the rooms with the portal gun at your disposal) with that of L4D. It should play like a L4D campaign, with some problem solving elements. The emphasis is on not only good and effective shooting (which are not always synonymous) , but being able to adapt and think on ones feet with more than just a weapon.
The map currently under development is the approach to Aperture Science. It will play out like a typical L4D level. The portal gun will not appear in this level as it is mainly to get the player used to a few different mechanics (such as not always having a primary weapon and being forced to use pistols, being on ones own, risk/benifit of traveling in areas off the beaten path).
It is still being decided if there will be both a single player version of the game and a multiplayer version. The overall goal is provide the player with a difficult enough challenge that feels like a real addition to the series rather than just a L4D map with a portal gun.
At the time of this writing, the aim is to provide the standard 5 chapters for the campaign as described in the valve wiki.This may change to be more than five, depending on a couple of different variables.
Newly revealed features are listed in blue.
All the standard L4D weapons make a reappearance but ammo is a bit more scarce
Melee only can knock back Infected and it is quite difficult to kill them with melee spam
The Portal gun makes a debut, taking the place of a primary weapon-Thats right, you have to choose carefully how to proceed
You may not always have your teammates (the other Survivors) to back you up. I suggest you get good with headshotting moving enemies and learn how to fend for yourself.
D.A.V.I.S. or the Data Archival Voice Interface System, the brother system to GLADOS is active. Will he be a bane or boon to the Survivors? Your actions will dictate how this persona of Aperture plays his role in the campaign.
M.A.I.S.E. or the Mannco Automated Internal Security Engram has also been activated. Will the player be able to convince him that they are not the main threat....or with the player be dodging bullets in addition to the attacks of the Infected.
Something seems amiss in the wreckage of one of the buildings. Could there have possibly been other survivors?
More info will come with time. Stay tuned.