Nice game! as a fellow novice developer I have some recomendations you could try. I noticed you used colliders that detects when a player hits a button (lights, doors, etc..) this gets the job done however you should try using Raycasting, it's super easy and will make it very accurate so that the message only appears when the players looking directly at the door knob, plus you can change the crosshair color. Also I noticed the mouse sensitivity was really slow, you could try bumping it up a bit, also if it isn't the standard unity controller make sure to times it by times.deltatime to ensure it's the same on every PC. The game looks nice, but some other stuff you could do includes making sure you're using defferred rendering, post processing, no MSAA, and you might even be interested in adding a higher quality skybox with HDRI and make sure the lighting is coming from it. Other than that it was a fun game! I expect great games from you. :)