The System Shock remaster was originally supposed to be developed in Unity, but unfortunately those plans went sour when the developers encountered numerous issues with performance, as you can see in the playable demo. The project is still moving forward, so don't worry about it being canceled, but from now it will done in Unreal Engine 4, which honestly makes a whole lot more sense for a game like System Shock.
If you're interested in how the transition has gone, and what the graphics in this newest version look like, you'll find the most recent gameplay trailer right below. Just do bear in mind that what you'r watching is pre-alpha footage, so don't be surprised if you notice some fairly stilted animations. Anyway, have a look:
System Shock will be coming to PC and consoles at some point in 2018, and if you would like to learn more I would recommend you head over to the official website. Additionally, if you would like to grab yourself a copy once it releases, and also help the developers out, you can find all of the various offers over here. For those of you that do decide to buy one of the packages, just make sure you're doing it to support the developers, and not to simply pre-order yourself a copy as that is a quick and easy road to frustration.