Maybe you could create a like a zombie rush game with barricades that you could build, and put like a TowerDefense game with that.
And its all FPS view.
Like SourceForts you have 15 min's to build and then the zombies come and try to get to your "last stand"\ "home base" etc.. and they will win if they would come to there.
And you could put like sub machine guns (build then in the build stage) and then when the zombies come you shoot them with it.
Like Warcraft 3 TD but 3D and like sourceforts + zombies(=awesomeness),
So what do you think?

Oh, you poor thing, prepare to get flamed to hell because you're Trying To Be Too Much Like L4D.

Nevertheless, you do realize that your idea could be employed with just about anything else (instead of zombies)?

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Truth | Sarcasm

It'd be quite fun, but its been suggested many times before on here. No reason why another mod group or something should make something like it.

It'd be fun but good luck making it.

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proof sol said it

There was a mod getting started up on Interlopers.net with this idea in mind, called Barricade. Check that out.

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Yes but you have it half done!
And I suggest that you will do something like this..

We wouldn't be able to do it in the HL2 engine probably though?

Is there a L4D SDK out yet?

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proof sol said it

You could With HL2 , you have zombie modules and you have the mod SF you could just program a bit more and make an awesome mod(like SF)

Sounds like a cross between nazi zombies, SF and L4D.

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monty : lol, everyone knows sf2 is never coming out

MelexM, we have no intention of doing this I'm afraid. We've already started work on our next version, and we're not going to stop now and change the design direction. Also, there are a fair few zombie mods out there already, it's been overdone to be honest. You should go and check out Barricade, apparently they are doing this.