Most of the games I played back in the day had some way of resuming your progress at a later date, whether that was an actual save system, a password system, or even a hidden warp zone. What were you supposed to do for longer games that had no way at all of resuming your progress after switching the console off? Get good enough at the start of it that you could play the game faster and eventually complete it in one go, or just leave the console on overnight and continue the next day?
(and yes, my Mega Drive is currently sitting powered on because I couldn’t think of a better way to keep my progress)
In one sitting. You’d have to get good at them by playing them over and over and over again. And they were really hard so that it would take a long time to get that good.
This was intentional. Games from the 80s had a lot more technical limitations compared to today and this was a way to increase their replay value. Otherwise you’d spend $30 on a game ($93 today) and beat a game in a couple tries, and it wouldn’t be worth it.