I've now played through the demo 1.5 times.
The 0.5 is for when it crashed on me on the second run-through. (Pre-alpha's gonna pre-alpha.)
Overall I'm nearly as impressed as I hoped to be. The "feel" of the place is definitely there. The other part that matters to me I can't really know about yet, and that's how intelligent the overall game seems. The original was definitely a protoshooter, but within that style there was a great deal of opportunity for the player to be clever in exploring the world and overcoming challenges.
The early mechanics are slightly different, but not nearly as frustrating as Dead Space (which I will until my dying breath consider a cheap rip-off of System Shock). The lighting design is very good, although some areas seemed to be DOOM3 dark -- as in, "ha-ha, I made it so you can't see and now I'm having a monster attack you, enjoy reloading!" dark. (Although there was a light switch.)
Nearly all my complaints are about things that are different in the remake demo from what I remember of the original game, which I've played for 22 year, so "memorized" is really not a sufficiently strong word for "why isn't [thing] where it's supposed to be?!"
For example, in the very first room, the Neurosurgery Suite, there's a medipatch where one was in the original game. So that's a proper touch. But after equipping the email reader from the closet, there's no audio message from SHODAN welcoming me to Citadel Station -- and telling me where the major areas are located -- as there once was. That audio not only still exists, but Terri Brosius has returned to do additional audio for the remake... so why was that voicemail excluded?
There are other small annoyances: the UI is barely functional; picking up usable objects causes a character animation to run that lasts several seconds and can't be interrupted (this looks very much like when you collect a new plasmid in BioShock, only more irritating); climbing ladders is painfully slow; climb animations can't be stopped; some of the level geometry is different from the original Medical level (not just blocked off for the demo but inexplicably slightly different); the initial puzzle is not a puzzle in any way, shape, or form; the SV-23 Dartgun that's supposed to be under the first energy recharging station is not there (nor is the dartgun ammo, which was a good initial reward for exploration); the game does not start with the wonderful options page from the original game that allows you four levels of customization each for Combat, Puzzles, Mission (story), and Cyberspace; there are no viewscreens (that can be destroyed) flashing images of Edward Diego; there are no tutorial text callouts showing you where things to click on are located; clickable things (like switches) aren't always obvious; collectible objects like keycards are hard to distinguish from textures; ...and wow, textures are horrifically pixelated when seen up-close. Also, the first level area of the demo had zero audio logs, which was
the driver of the main story in the original game -- the absence of these, even in the demo, bothers me a little because of how important they are.
Something else I didn't care for: upon reaching a door, the demo abruptly just ends with no warning. It just stops. And tries to bring up its Kickstarter page in a browser, which is a big no-no for me. (Do not touch my stuff without permission.)
Finally, there was that crash, which I appear not to be the only person to experience. (Very annoying: it covered all of my screen except the task bar, including the Task Manager window that would have let me kill the dead process.)
Some of these things are trivial. Others are absolutely explainable by "it's just a pre-alpha demo." Certain other things... I guess we'll have to see.
On the other hand, leaning is implemented as in the original System Shock. And WASD+mouselook feels great, which even I consider a required change from the original game's mouse-driven movement scheme. And it looks like items in containers (including corpses) are generated at the moment when you click on them, just as in the original game, so that's nice for those of us willing to click and reload for a while until we get teflon-coated bullets.
(I'm assuming reloading will be as fast in the remake as it was in the original. I really don't want to have to wait 10+ seconds to reload what's presumably a pretty simple world.)
The audio is very good -- it's plausible for the world and positional, as I would demand from a game originally made by Looking Glass. I also noticed the location-triggered game music that's suitably disturbing (another nod to BioShock).
Another nice touch: the planet Saturn is visible outside a window, and if you watch for a bit, you can see that Saturn moves as Citadel Station rotates. In fact, if you look up when you're at that window, you'll see parts of Citadel Station itself. That's a nice feature, presumably inspired by System Shock 2.
On balance, I'm mostly seeing what I hope to see at this point, and the things I don't see I mostly don't expect to see right now. As high as my expectations are, I definitely don't feel bad about backing this Kickstarter.