How long will Amnesia be?

[Yuhaney]

If Overture were No One Lives Forever 1 and Black Plague were No One Lives Forever 2, Requiem would be Contract J.A.C.K

Now that´s a bit too harsh I think! Requiem ain´t that bad!

Ok, how about this instead: if Overture/Black Plague were Deus Ex, Requiem would be Invisible War. A decent game on it's own but a failure as a sequel

I thougt requiem is more like a side-story than a real sequel.

It's not a sequel. It's just an expansion to Black Plague.