Unforgiving
You young whipper-snappers with your save games and infinite continues! Back in my day, we had to beat games in one sitting. And when you ran out of lives, tough luck, buddy!
I've been playing Fire Emblem again (I never finished it the first time). Fire Emblem reminds me of old-school games. It's quite unforgiving: when one of your characters die in battle, they're gone for good. And don't even think about reloading the in-game save hoping that your character will dodge instead. The game automatically saves after each move and the random-number seed does not change when you load an in-game save. Combine that with having to overcome 3-to-1 odds in the later levels and you get a lot of mission restarts.
Old-school games like Contra and Super C are unforgiving like that. They give you three to five lives and expect you to get through the entire game. If I remember correctly, you're given two continues in Super C. Not quite enough to cover the hundred or so times you could die before reaching the end.
That's where cheats come in. I always played Super C with a Game Genie cheat that gave me one life for every enemy I killed. I could beat the game with that cheat, although would you believe it if I said that sometimes I'd still have to use a continue?
I remember games being so much harder when I was younger. Partly because I royally sucked at games, mostly because games were much harder. Beating a game without cheats used to be a major accomplishment. Now, it's more like an expectation.
How much harder were games back then? I think an accurate comparison would be: Ikaruga without infinite continues; Viewtiful Joe on Ultra-V-Rated (maybe V-Rated) difficulty.