Hey nice work. Felt pretty interesting flying around and exploring the place. I think there were a couple things however that made the game feel a bit less intuitive.
First one is the controls. I felt the fact that there was no acceleration, the camera followed the character directly, and having no deceleration made it so that the movement was particularly jarring.
Next is that the followers had colliders attached to them. Sometimes I would get blocked by the followers, and their collider didn't seem to really fit a purpose so I would probably get rid of them, maybe set the isTrigger tag to true so you can detect if the player touches them without blocking.
I would also say that maybe have the unlocked doors visually change.
In addition, towards the end I dropped the safe key but didn't know where to find it again - wasn't sure if I'm just dumb but it didn't seem very clear.
Lastly, the wall of text in the beginning I didn't read at all. I would probably split it up into multiple different prompts with a next button, and put the controls in there too as you didn't mention the drop button (Q) in the game. Anyways, overall good job!