FFVII has really crappy 3D, and sometimes awkward transitions between presentation modes. Still, some of what Square pioneered in that game remain: fixed cameras, character oriented controls, etc... (where the control "left" does different things depending on where the character is facing)
They have gone back and forth on open world vs rails or corridors, and I find the open world, like FFXII, the most enjoyable and replayable of the titles.
When FFVII was released, it was one of the first my wife really wanted to play with me. We played lots of games, but the vivid nature of the story, lots of activities, puzzles, mini-games (Oh, how we spent time on Chocobo breeding...), really made for an awesome experience!
But, an attempt to play it today is tough. The really poor visuals often get in the way, and it just reeks of old.
This is true of many 2D titles too.
One difference is how abstract the game is. An old 2D game, such as TEMPEST, or DEFENDER, actually looks and plays well today. It is what it is, and that isn't much, but the challenge is there, presentation sufficient, and it's sort of timeless.
Those games that went for some realism, or that made more identifiable characters seem to age a lot more quickly, though somebody up thread mentioned SONIC. Yeah, that one is still relevant, and is a stellar example of a timeless presentation involving simple, easily understood mechanics.