Perhaps the best way to explain the experience of playing a preview version of the game is recounting one particular incident which occurred while I was making my way through some flooded underground tunnels.
I'd previously seen something terrible. The ghastly, stretched face of a wretched creature. I'd turned from a rockfall and it evaporated in front of me before I could get a good look. So I knew there was badness out there. But stood in the tunnel, the threat wasn't visible. Its foot-splashes in the water were. But it could only get me if I was in the water too.
So it became a case of leaping from crate to barrel, attempting to clear gaps without making any splash at all. Hit the water and the invisible beast would crash its way towards me, claws slashing. Then inspiration struck. Pick up a crate, throw it down the tunnel. Yes! The creature stalked after it, offering a brief chance to run for the next safe surface. Or better, the fetid flesh of a discarded human arm. That kept him distracted for just long enough to turn the crank handle to open the next door.
The terror this sequence evokes is remarkable. Jumping onto crates in time because a moment of panic, the noise of the monstrous footsteps splashing ever nearer. It uses the game's omnipresent physics to impressive effect.
That's Frictional's other trademark. Where most FPS games will now have Havok or similar providing reasonably accurate physics, few use it for much beyond looking nice. Amnesia looks likely to rely heavily on it. Reaching a hole in a ceiling doesn't require finding the correct ladder, or pressing the right button. It involves gathering detritus from the surrounding area and fashioning a crude staircase.
Machinery that must be manipulated is also dependent upon real-world rules. Raising a trapdoor using a pulley makes a great deal more sense here than gaming's usual invisible mechanisms. Cogs fit together and work accurately. Objects move appropriately, and while Daniel seems to be able to throw unrealistically far, things crash down satisfyingly - or even better, if breakable, will smash. It's peculiar how special it feels to pick up a bottle with a key inside, and deliberately slam it against a wall to get it out.
Of more concern at this point is the story. From the few hours I've played, whatever was going on remains a mystery, and not the good sort where you're pulling threads together. The sort where you just don't have much of a clue what's going on around you, despite multiple letters, notes and that gaming peculiarity of the widely scattered diary. The motivation is progression, but why is less clear.
Also, while the sanity idea is interesting, it does seem to be somewhat mechanical. You will go slowly insane, but taking the rather literally named Sanity Potions makes you better. It will be interesting to see if that makes more sense in the context of the whole game.
For now, the awful biting, crunching sound that seems to follow you so often seems to be sticking with me long after I've played. The impression so far is of a game that while extremely similar to Penumbra in style, is looking much neater, and managing to be far more sinister. Crunch crunch crunch.
Amnesia: The Dark Descent is due out for PC on 8th September.