Only a few games are played regardless of passage of time, The games which I still deem playable from the 1990's (mostly after 96) that have withstood time.... so far.

1- Castlevania - Symphony of the night (still plays and looks good)

2- Broken Sword (hand drawn art will almost never age)

3- Thief 2 (In the darkness you notice very little)

4- Metal Gear Solid (looks good, camera and gameplay some will dig, but allright to me)

5- Alien versus Predator (looks pretty good and still kind of scary)

6- Silent hill ( reaching limit)

7- Aquanox (Nice graphics for the time)

8- Final Fantasy IX (with enchancements of opengl and shader on an emulator)

9- Rayman

And that's all I remember, if you know some other which withstood and still playable today, post away.