This is the shareware demo version of System Shock, featuring a slightly earlier version of the first deck. Originally released by LGS in early 1995, now edited and patched with the
SHLINK loader to run on modern computers - go to \bin and run shlink.exe, and don't forget to set the resolution in video/video mode menu to 640*480 and the messages in audio/audio options menu to "both" once you start a new game. Controls are standard WASD, and E toggles between the use mode and the shoot mode. Note that there is no music. A few binds and other options can be edited in XCYB.CFG and shlink.ini (fullscreen on/off, for example).
Update: the folder structure has been rearranged to allow the EE patch to work with the demo. Download
shock-patch_rc1.7z from GOG and extract it to the SS1 Shareware folder, run sshock.exe and the game should start. The original shlink.exe in the \bin folder will still work even after applying the update.
Have fun,
systemshock.org