Sequel to Penumbra Requiem?

[spukrian]

So I wonder is a sequel coming out?

The Penumbra series is done. There won´t be anymore sequels.

BTW , I have some questions - What was that code in the end used for ?

The code is used to find some secrets. Look around in the forum and you´ll find out what.

What are those additional texts when collecting all the artifacts ? (I collected two of nine) ,

Well,

Spoiler below!

if I recall correctly you get to read more of Philip's email to his friend, but of course my memory is quite hazy.

and if a sequel isn't being made is there a mod for it on Half Life 2 Engine?

I don´t think there is any mod for Half-Life 2. Personally I think that the engine Penumbra uses is much better than the Half-Life 2 engine.

Edit: Does this game take place In Phillips mind?

Well, that´s the common interpretation, my opinion is however that

Spoiler below!

the Tuurngait is torturing/testing Phillip, trapping him in a mental hellhole.