Hi! Your game is very immersive and lively. I've had a good time exploring it. However, there are some issues that put the game in unwinnable state in a way that's not immediately evident.
Spoiler warning
The MRI Scanner can be activated only once in the game, so it’s clear what will happen if the player does it before the endgame. I think this is a major bug. The average player will be extremely frustrated at the endgame and will certainly not restart the game from the beginning at this point.
The safe combination seems to be randomly generated, but it’s not saved in the game persistent state. It’s regenerated on every restore and every time the player rewinds the tape and replays the message.
That’s a minor one: If the player puts the ledger in the backpack before entering the “Main Hallway @ Dumbwaiter” room, then the “enemy pursue” state will not be triggered. That’s the ONLY room that will trigger the pursue, so the player will roam indefinitely without resolution, even when the ledger gets shown to other NPCs in other rooms.