The sign at the start saying no anomaly = go forward, anomaly = go back made the rule of the corridor clear in two seconds, and the gold scanlines with the ceiling lamp gave the hallway a real sense of dread. The sanity bar in the corner is a nice tension tool. What I missed was feedback on what counts as an anomaly: after the tutorial the corridor just looked dim, and with the camera needing a click to start, I walked a few steps unsure whether input was captured. Show a short pointer-lock prompt that disappears when captured, and flash the sanity bar when a wrong choice costs something.