You die and die and die. Load up another save, maybe. Finally, you emerge triumphant over the boss battle or end sequence you've been struggling with. Nowadays, you're likely to get a big shiny, fully-voiced cutscene topped off with swelling orchestral music. But that wasn't the case 30 years ago.
Back in the day, the games just stopped. You were lucky if you got an animated sprite mouthing words at you. But there was little in the way of fanfare or celebration. Instead, you got a pithy acknowledgment that essentially said "yes, you have in fact finished this game". We've assembled the best of these old-school sudden-stop endings in case you've forgotten their brusque games. Watch them and ponder how far games have come. And be glad that the word "congratulations" gets spelled correctly these days.