Okay, when we talk about older games compared to newer games, let me say some stuff.
First, I don't think that older games are automatically better than newer games, regardless of challenge or gameplay Some are, but overall, I prefer newer games.
There are features that you can still take from older games and they will be still good. Old Jump and Rund mechanics work perfectly on games today as they worked back then. It's no coincidence that Super Mario games are still so popular.
Soem stuff could be however gone for good. Who needs a passowrd saving system anyway? That's the most annoying part of Mega Man. I'm also someone who thinks that a game does NOT need any extra lives. A well made checkpoint system is sufficient enough. And when I look at 8-bit Boy (a game that got well appraised for reasons I don't understand) where an extra lives system does not make any sense at all (when you die, you have to go back at the start of the level. if you loose all lives you have to reload a save game... which is at the start of the same level) I think lives in general should go away.