I had a quick google around and found this:
http://www.tauniverse.com/cavedog/amen/index.shtml
Theres a vid on there but no demo - apparently it was only 50-60% done when they pulled the plug...

So your goal is to play at least the demo of every single FPS ever?

Including the likes of Tek-War and Fortress of Dr. Radiaki?

Sherlock Holmes - Silver Earring?

Not exactly... I just love hunting up hard to find FPSs in some form or another.

Same for me :) Anyway Amen would have been a good "Deus Ex" precursor.

no

Its been a long time, provide some clues.

too many...

I do only know: Vampire: The Masquerade - Bloodlines

but it does not look like that :)

The rez looks just a little to high to be Gabriel Knight 3 but I'll go ahead and guess that anyway...

wrong

Looks like the same kind of engine used in Amnesia, Penumbra, Sherlock Holmes.

My guess is Still Life

ok

hint 2: the name of the game sounds very similar to my favourite ps2 game (another horror game)

hint 3: the meaning of the game's name can be well understood by the readers of Lord of the Flies
no
hint 4

See the new Alone in the Dark game starts in a hotel, there is a hotel in Silent Hill 2 and quite a few other titles. Its quite a common location for horror based games.

Its not an action game, it is looking like one of the adventure games in the mold of Sherlock Holmes, Nancy Drew, Amnesia, Penumbra, Post Mortem and the list is endless. Problem here is a lot of those types of games look exactly the same.

Your clues are not to helpful either, they are very obscure and by the look of it the game you have picked is also obscure which takes the fun out of the whole thing. I have read Lord of the Flies and just cant see where you are coming from with that. You have the reference to Satan towards the end of the book and pigs head but I cant place that with any game.

lets see if my hints are gonna be not helpful to anyone... in that case I will tell what is is