Nice concept, the flicker could act like a warning signal. Maybe have the code be a loop that keeps the system alive, and every few seconds the screen flashes a corrupted pixel, building tension before the final crash. The heartbeat feel will make it feel urgent. If you want to push the horror angle, let the flicker reveal a message in the shadows—something like “You’re not alone” before the system goes down. That twist can keep the audience guessing. Try layering some glitchy audio too, it’ll give the scene that cold, digital pulse you’re after.